Either way, make sure whatever bike you buy fits!!
I agree that CX bikes are a little more versatile (you can fit wider tires), rugged, and probably heavier than most (racing) road bikes out there. Gearing won't be an issue unless you develop into a really strong rider. (And as a beginner, the weight of your bike won't really matter.) But in the brakes department, cantilever brakes are a bit of a pain to adjust, while disc brakes are a bit heavy and aren't that widespread yet. If you buy a CX bike for road riding, you will also want to buy a set of slick tires (and tubes), as CX bikes come with tires with wider, knobbier treads.
Another option is the "comfort" road bike which is basically a standard racing style road bike with a more relaxed geometry - taller headtube, longer wheelbase, etc. Quite a few companies make road bikes specifically for this purpose. If you don't envisage yourself ever wanting to ride with wider than 25mm tires, or want disc brakes, etc. I'd go with this option. (Personally, I much prefer the option of running up to 32mm tires on my bikes.)
Last edited by idc; 02-19-13 at 08:13 AM.