You guys are missing the point....start-ups are considered young, bold, attractive. The heavy hitters only look at the VC ones. There are, for example, small beverage companies slowly climbing the cliff. Triple-S Michelada (Brownsville), for example, is a small company causing quite a stir in the beverage world and is virtually unknown at this point still. Zimbio, Technorati, Orkut are other ones that should be up and coming pretty soon. No matter the company---the class product they represent is the difference between $$ and $$$$$$$$$$$$.
SiTime is not alone in MEMS timing devices, many others including IDT are catching up fast. These devices are NOT replacements for more accurate TCXO's/OCXO's so the Silicon timing market (pegged at $1.2B total, a subset of frequency control components market at $4B). Of this, the MEMS oscillator market is projected to be at ~$440M by 2017... so the market is starting to get crowded.
An 11 year old company with no income is not a startup, just a money sink. Sorry, but the VCs have probably diluted all the employees shares by now so there's not much motivation for the working stiffs. Good luck anyway.
Nantero made the list? Really? They have been around for more than 10 years and there has been little to watch. Why start now? :-) And since when did IMEC become this authority in technology trends. They mostly seem to be a touch behind the leading edge.