Limiting "scope creep" is where the Project Managers really earn their money. If they're not successful, they lose money - if more bosses realized this, endeavors like BIM would have a high success rate.
Anyway... My vision is to keep BIM engineer-oriented, rather than architect-oriented. That is, while I support the architect as "master builder" and my job is to capture their vision in my structural design, a BIM effort - that is, a team effort - has to be dominated by good engineers: and I want an architect who thinks like an engineer (we have two of them on my team, we're blessed).
I also have a vision (I have visions...), that I'm sure we all share, of a BIM project going from the charette to O&M and back again when time for renovation comes.
What I see as the toughest obstacle is forcing those in project management to embrace this technology (in the sense that they'll pay for it) and let us work things out. Some of the PMs, those whose last engineering project got them a "C" in senior design, automatically see BIM as just another widget to sub out and check off a milestone. Granted, that's good for the subs, but then someone has to review the BIM - or do they? The final product that's been paid for is a set of plans and specifications, how those were produced doesn't matter to the bottom line.
Now, if we engineers are going to be "faster, better, smarter" how can we justify spending the several months of intense activity learning BIM to the point where we are good at it, when there's some specialty company that already is the master of BIM? It's hard enough to justify the need to enforce CAD standards (who cares? everything is black and white in the end!), this BIM stuff might be a wash...
As a structural, the idea of getting in on the charette is appealing because I can "sell" the customer (and the architects) on framing options early, instead of at the 35% stage - when I find out that certain framing isn't appealing, and I didn't quite know that because the charette report was never finalized...