Interesting. I've noticed the opposite, my 2010 MPB has been running a lot cooler, or at least the fan doesn't kick in as much. With Mavericks if I was using Matlab and listening to music the fan would run pretty good. However with Yosemite, right now with Matlab running and listening to music the fan is sitting at idle 2000 RPM and CPU is at 128* F.
When it gets hot have you opened up Activity Monitor to see if there are any processes using a lot of CPU?