The daVinci is not built on one or even a few patents so it's not like someone can put out anything remotely as capable as the current daVinci starting in 2012 or even 2018.
The impact of a few patents, even if they were foundational patents expiring in 2012 should be negligible.
To consider daVinci as a single product and think that ISRG should have additional products is to miss the fact that daVinci is a platform. Their products in a sense are the different procedures they are capable of doing as well as the technologies that are and will be hosted on their surgical platform.
Thanks for the response Fish, but I still think those expirations will have an impact. I do understand the idea of a competitive platform. The iPhone had a "platform" monopoly until Blackberry and Droid also became competitively designed.