TheEnigmaticT: To answer the questions asked about patching:
GOG provides you guys with the game DRM-free. Like pretty much all of our games, we provide you guys with the most recent patched version available at release. The Witcher 2 is an unusual case, of course, since it's a new release instead of an old one. GOG won't be hosting patches because we're not the publisher. You'll need your CD Key from GOG to be able to register your game and install any future DLC or patches.
There remains no DRM on the game, no install limits, and nothing prohibiting you from backing your GOG title up onto DVDs or whatever form of media amuses you most. Further, there is no activation limit for how many times the patch can be downloaded off a particular serial code from GOG.com.
I don't see how, even in the most general sense, that can be considered DRM, but you're of course free to point out the error of my ways in great detail by hitting that "reply to" button below.
If there was a law obliging developers to release their software DRM-free, in my eyes your implementation would obey the letter of the law, but not the spirit.
I don't think it comes as a surprise that people looking for DRM-free titles mostly wants to avoid depending on external entities authorisations to be able to enjoy the games they buy out of various concerns, like not being able to use the authorisation tools in the first place (gaming rigs without an internet connection or with problematic connections), being subject to technical or implementation issues preventing the authorisation process to successfully complete, being cut off their games when the authorisation servers are, for whatever reason, no longer in place.
With your implementation, you're restricting the notion of enjoying the game without depending on external entities authorisations to the installation and execution of the game in its original release version, which may or may not be satisfactory depending on the state of the game at release (in terms of working in the first place, being bug-free, and in a not univocally definable "complete" state).
When Stardock followed a very similar route, the spin they tried to give to the concept was that the content people not registering didn't get access to was additional, something free, not needed for the product they bought to be "fit for the purpose". Customers of some of the titles released lately by the company may disagree.
Now, with all the respect for CD Projekt RED and confidence that they may release an as bug-free as possible game, patching when it comes to PC gaming is the norm, not the exception.
Bugs may slip past even the best Q&A department, not all possible configurations can be tested. In The Witcher 2 case, we already know that proper support for non-16:9 ratios won't make it to the release version but it's planned for a future patch: while I wasn't as worked up as some others for the lack of proper support for 16:10 monitors - having a 16:10 monitor supporting not-native resolutions without scaling (or with a very good scaler, when it's preferable) and fairly good black depth - the idea that such support may count as an additional feature rather than something to normally expect sounds awkward.
A lot of emphasis on the fact that registration is optional has been placed during the Spring Conference, sounding fairly similar to the Stardock position, but trying to treat patching like something additional, that can be detached from the notion of fully enjoying the game seems fairly questionable to me.
And with the system you're putting in place for patching, the concerns I expressed at the beginning of this very long post, are justified: servers may malfunction, serials may be blacklisted if a keygen hits a specific key too often.
Backing up installations and keeping track of registry changes while installing / patching the game may help with the other concerns, but that's an hassle each of us will take into account when deciding whatever to buy and at which price point.