Yes you can, RAID 0 is essentially recognised as a single drive and so copying to a RAID volume is no different than a single hard drive.
The one thing to consider though is whether you are doing RAID using your motherboards RAID chipset or through drivers in windows. If its driver reliant you may have problems migrating windows without getting a BSOD since the appropriate drivers will not be installed. Your data will have been copied over in its entirety despite windows not working.
Either way, migrate your OS without deleting the original and see whether you can boot (you'll have a backup if anything goes wrong, practical application always gives you a definite answer).
What kind of speed can I expect in raid 0? I'm getting 522/502 now on Samsung 840 pro.
Well THEORETICALLY you can get up to double the speed if you stick another Samsung 840 pro in and it performs just as well, so effectively you would be looking at 522*2/502*2.
In reality it comes down to the stripe size you chose and the file size that you're dealing with. For sequential writes with a big file (and assuming you have a good RAID controller) you'll be looking at very near double performance.
On files smaller than your stripe size only one drive will be utilised so you wont see any speed improvement. Typically 128kb stripe times are good for a SSD RAID volume since you don't really have problems with access times (unlike mechanical drives).
Overall, from a practical perspective I think you'll find things are twice as fast since operations less than your stripe size happen in a fraction of a second on an SSD anyway.
Other things that might be important to you:
RAID 0 restricts your drive size to 2x the smallest drive you have.
If one RAID 0 drive fails the data will become irrecoverable off the other since its split between both drives, so try not to rely on it for storage of irreplaceable files.
You should see around 900mb/s to 1gb/s depending on the raid chipset. But in real life and as a boot drive it will slow you down. It adds more time to the pc startup, to initialize the raid, then you save with the higher speed. Access time increases since now two drives have to search/sync...