I think that this will go fine, for WP_v3.4. Longer-term, having the 'experimental' caveat highly-placed will be valuable.

We've been to this movie, repeatedly. See e.g. The Mythical Man-Month

In our favor, early WordPress was pretty close to a classic one-man project ... which despite its ultimately fatal limitations, remains the primary creative venue in software ... in large part because if obviates TMMM, et al.

Matt Mullenweg, and some of the other key/core personell, clearly know what they're up against. That's the main thing. It's an experimental process, feeling your way into it step by flexible step. The early steps have already been taken, and the stumbles were recoverable.

Some peripheral, less-aware participants will get tender parts of their anatomy pinched in the wringer ... but the effort overall to bring more skilled coders, and a 'degree' of rational organization to the WP-Dev schema, looks healthy & on-track.

Good-on everyone involved.