Given that evolution is the name for change, surely we will deliberately make changes. Initially to eliminate or provide fixes for diseases but also to 'improve' our offspring in various ways. But will such improvements be subject to patents and possibly not able to be passed on without the correct chemical activation code to prevent unauthorised use of proprietry genes? We could end up with all our usual genetics, able to work as normal but if you want those longevity genes to be passed on you'll have to pay your license fee. Even to have them keep on working beyond a limited time. Still, the patenting of Genes is currently under scrutiny; I doubt the patents for existing human genes will survive the legal battles within those limited jurisdictions that actually recognise their validity - being discoveries not inventions - but genuinely new ones could become the proprietry property of medical genetics companies.
Our genetics are already the basis of bigotry and discrimination and, unless the changes somehow decrease those urges to put people most like ourselves ahead of those more different - very unlikely - I have no doubt it will become an issue. But making changes will potentially make the recipients of them potentially more different than is comfortable. The highly intelligent kids of average parents is already a difficult situation for those parents. SuperKids probably won't find their situation easy.
Discrimination is very widespread; just failing to be good looking limits opportunities and sees people subjected to derision and abuse. Any greater good will probably not be the basis of choices for engineering of offspring and probably face criticism for attempting to engage in social engineering; more likely health, looks and advantageous ability for those individuals - allowing them to better compete and dominate - will dominate the choices.
I expect the altered will face discrimination, at least at first, especially if it upsets the religious and it surely will. It could take some time before it would be the 'altered' that dominate and discriminate against 'normals'.
I did watch Gattaca and note that it played to the fears of 'normal' people being supplanted; us normals sympathise with the very capable but genetically flawed main character.
In SF writing especially, it's a recurring theme, sometimes from the perspective of 'normals', sometimes from the perspective of 'altereds' and sometimes both. Mostly they don't really add that much insight but occaisionally can be both a good read and cover some of the issues and dilemmas. Not much on my bookshelf right now but there is one with such a theme called 'Blueheart' by Alison Sinclair. Not a well known author but I thought worth reading both for looking at the tensions between 'adaptives' seeking to make their one-off adaptations to a water world into 'germ line' changes that would be passed to their children as well as some of the issues surrounding supplanting an existing ecosystem with 'suitable' life. What's improbable is facing those issues so far away in both space and time; the dilemmas are upon us right here and now.
The stuff we are made of is highly multifunctional and making sense of all the interactions is surely a key to successful genetic engineering for specific outcomes. Likely there are multiple ways to arrive at outcomes and if one that is in fact inferior but by virtue of superior marketing comes to dominate there could be consequences down the line.
Just how capable we will be as custodians of our genome in the future is hard to judge from here; foresight could result in greater genetic resilience, or at least leave us with no less.
Commercial considerations - maintaining patent rights and preventing unauthorised use and distribution could be a greater drive to preventing long term problems than foresight; so far the biggest uses of genetic engineering is in crops and mostly these appear deliberately designed to not breed true.
Being wise looks a little unlikely from here with humanity about to rush in to where the wise choose not to tread.
Whether genetic manipulation is evolution depends on your definition; from Chris Colby's online Introduction to Evolution the definition is pretty basic - "Evolution is a change in the gene pool of a population over time."
The means of such change is not limited to natural selection - "The mechanisms of evolution are mutation, natural selection, genetic drift, recombination and gene flow."
From the definitions he provides it looks like genetic engineering probably might be classed as either mutation or gene flow that comes from outside the species. He gives a natural example of genes being passed between species of fruit fly via a mite. But I suspect deliberate manipulation probably deserves it's own classification. I'd be surprised if, by that fundamental definition as changes to the gene pool in a population, that it can't be considered a form of evolution.
Barbara, from what I understand not all evolutionary changes are a consequence of changes to environment; mutations happen when genes don't replicate precisely and that has been happening since the start. If that mutation proves useful, even within an unchanged environment, it could lead to greater success of those who carry it. It's not even necessary for change to be beneficial to be passed on; a clever proto human could probably tolerate a lot more maladaption than other species - it could even have been the driving force behind some of the behavioural changes such as the use of clothing, tools and shelter. Certainly changing environment changes the balance between variations within a population as seen with the moth example; it can provide the tipping point that sees some variants within a population succeed whilst others fail. But it's not a prerequisite to evolution. I should add that I think it's irrelevant whether we consider genetic manipulation to be a form of evolution or something else - it has the potential to result in accelerated change to the human genome.