The graphics when driving in the rain are below par at the moment, but I guess this will be dramatically improved in the final version? The short movie about a rain experiment from ISI way back in 2010 already looked much better as yet in the beta.
They have mentioned alot of things are missing from the weather system, even aquaplanning is coming! We do seem to be missing alot of the weather apart from the actual rain, I haven't seen a reflective track yet for example.
Well do you have road reflections (or was it environment reflections...) on? =) But yeah, many of the effects, even those seen in older videos, have been in and out of the game, and are currently out. It'll get much better than this before release. =)