OK, I downloaded and installed Real Alternative (there is also a Quicktime Alternative).
First test: went to the BBC News website and watched some videolips. The Real logo comes up when you loading them, and it looks exactly like the original Realplayer. Worked fine on the BBC's 225kbps streams.
Second test: download some full RealVideo files (not just streaming ones) and watch them in my 3rd party video player (BSPlayer). Unfortunately, couldn't find any so couldn't test it!
So, it appears they have reverse engineered the RealPlayer software (hence the logos). Either that or it is just a very close copy!