We have been giving presentations on BIM at Tocci for quite some time now.
Recently, we have actively decided that we need to stop overselling BIM & stop making promises we aren't 100% we can keep. I think it's a good decision; although, we haven't really made any specific promises in the past, just general 'talking up' of BIM. It's tough because we're so excited about it (both internally as a company and externally as an industry), but it's definitely something we all need to be aware of.
Lately, when I attend BIM presentations, that is one of the things that drives me crazy. I don't want anyone to build BIM up so much that it cannot meet expectations. In the end, that will only make it harder to integrate BIM into the industry.
So, please: If you're presenting about BIM to anyone, don't oversell. Speak realistically, bringing up the good, the bad and the ugly.