Yes but shouldn't. You'd be out of your mind to RAID 0. RAID 1 (mirror) ehh you'll be okay'ish; see below. Granted no two drives perform 'exactly' the same.
I do a lot of RAID, and I am so picky I want the same 'batch' of the same exact drives.
In RAID you get the 'LCD' Lowest Common Denominator:
Slowest speed (performance).
Smallest size e.g. 750GB + 1TB (250GB of the 1TB is lost)
edit: Further, IMO don't mix brands, each brand has it's own error reporting; not a good idea to mix. Also, ALL consumer WD lack TLER, so I never RAID them. See -> http://en.wikipedia.org/wiki/Error_recovery_control