Apple seeds OS X Yosemite Developer Preview 2 build 14A261i on Tuesday, June 17, 2014.
The first OS X Yosemite Developer Preview was too buggy for my 2010 MacBook Pro. The font doesn’t look right and I suspected that it was designed to look best on Retina Display. The support for NVIDIA GeForce GT 330M was pretty abysmal.
I have not had enough time using OS X Yosemite Developer Preview 2 to find out if it’s going to run well on older Macs. Time will tell.