Thanks very much for this great thread. I was wondering about this, as I've just purchased my MacBook Pro 13" early 2011 and upgraded it to Yosemite.
This evening I've tested the above terminal command for 512MB > 1024MB on Yosemite 10.10.0. Graphics were already running at 512MB VRAM due to the MacBook having 16GB RAM.
The initial result following restart: Boot was very slow, and upon login VRAM showed as
3MB. Terrible graphical performance.
Next step was to recover my backup .kext and restart; 3MB issue persisted following restart.
Then, downloaded and ran the following utility to repair kexts:
http://cvad-mac.narod.ru/index/0-4
This restored my original 512MB VRAM configuration. Next and original step was to get to 1024MB
My process on Yosemite to get 1024MB:
1) Run the original terminal command in this thread for 512MB > 1024MB (and assuming you can replace this with the upgrade of your choice)
2) Run the above-linked utility in this post directly afterwards
3) Restart
4) Enjoy
Graphics now test successfully at 1024MB VRAM. Whether it will survive a software update - I'm not sure, but easy enough to repeat