I also think that having the community around will bring up ideas for application blocks that MS might not have considered. But when they see one really taking off (Application Updater, anyone?) they will take it over and give it the ol' MS effort.
Really? I can't see how the fact that they'll only be created some instead of all invalidates any of your concerns for the ones they're not created.
JDM: no, some of the concerns are still valid, mainly the one of quality control. But some of them were relieved. For example, I was having trouble figuring out why MS wants to drop application blocks and remove responsibility on their creation from itself. That has been addressed.
All in all, if MS will continue with the same effort, but the community will be *adding* to these efforts(instead of replacing them) I can see how there would be motivation top move forward on this.
The issues of quality control are tough ones, but can be worked out if addressed properly. (at least that's what I hope)