I too would love to see something like this implemented. However, haven't there been efforts like this before that all have failed? For example, I remember (but cannot find) a thread last year that suggested we do the same thing using IRC and some special software. Or the thread about using Google Wave during kickoff (I think this idea had mild success to put it best). Another example is the (or lack of a) FRC team naming convention for twitter.
In order for this idea to take off, there will need to be several experienced and respected CD members using this system who will attract teams looking for help, and everyone would have to adhere to some set of standards. Some how this has to go viral but in an orderly fashion.
Ideally, a website like CD or TBA (something that has a big reputation in the FRC) would "sponsor"/promote/coordinate it. Realistically, neither of these two sites are going to want to write code for video conferencing (although there might be an open source API out there...).
What they could do is have a page that lists all the team's unique skype or whatever ids with a description of what that team has offered to give advice with. The rest would be up to those teams who gave their name.