It's probably not a bad starting point as Bioware also made the KOTOR games which are fairly accessible. When I played KOTOR it was the first 'proper' (i.e. not Diablo 2!) RPG I'd played since Shining Force 2 circa 1997 but it is quite captivating.
Basically once I'm done with Oblivion my next choice of RPG will be between these:
-Mass Effect: Bought it about 2 years ago when it was on offer, need to give it a proper go
-Dragon Age: Should be the best, might give it time to mature (patches etc) first though
-Morrowind: I adore FO3 so have started checking out the Bethesda back catalogue.