Virtu offers two modes....
1) iGPU as primary, dGPU as virtualized
2) dGPU as primary, iGPU as virtualized.
First mode will let you use iGPU as graphic output, using it as primary GPU for 2D and video decoding tasks. dGPU will kick in for 3D games and remain idle for rest. Since dGPU is virtualized it will take little performance hit, so far on an average it seems to be around ~10-15%. Although some games like Metro 2033 have shown the performance hit to go as high as 40%. There is some power saving in this mode, since dGPU remains idle most of the time. However it's not a lot as the current generation dGPUs have very good idle power states. Plus, there is a issue with wrong identification of DX runtime (DX10 vs DX11) since difference between iGPUs DX capabilities vs. dGPU, in some games. Mostly this good for average users or light gamer crowd.
Second mode will let you use dGPU as graphic output. This will be quite like using your regular dGPU as you would use now. But this mode also gives you access to QuickSync. The QuickSync performance takes a very minor hit even in virtualized state. So this option is most viable for gamers and enthusiast crowd.
As for SSD caching... the benefits of this can be questionable at this stage. But as SSD prices go down, specially for smaller capacity SSDs. throwing a 20-32GB SSD as cache could give a significant benefit as cache versus the traditional mechanical drive. Pure SSD setup will always trump this, but think of this as stop-gap solution for users on budget. Buy a second-hand or smaller SSD, throw in as cache and still get a good performance boost compared to regular HDD. Use the money saved on better GPU or other things. Of course, if your budget permits, getting a good 60-80GB SSD is always preferable. But I don't think it's right to completely write off SSD caching or hybrid drives. I recently upgraded my 3 year old macbook with Seagate Momentus XT drive, and with 7200RPM and SSD cache the overall improvement is noticeable.
On top of everything else, Z68 boards doesn't seem to be that overpriced on their P67 counter-parts. So Z68 is definitely a win-win for users, specially the enthusiast crowd. I was waiting for Z68 boards, however, now for some other reasons I've decided to push my upgrade schedule till Ivy Bridge.
