Strictly speaking, yes.
However, I suspect that legislation will be introduced that will deal with the current situation and the indiscrepancies surrounding the whole retrofit situation.
In the early days (3 or so years ago) of retrofit kits, the quality of the bulbs was such that fitting them was a very hit and miss affair as to whether you'd end up with a respectable beam pattern and cut-off.
The modern kits have improved dramatically and the one I fitted for A2GoldenMiler yesterday was sharp and well defined and perfectly within legal limits.
The popularity of these kits is growing so much that there will have to be some definite word soon, in terms of their legality - Audi Driver magazine even had a feature on fitting them last month!
To me, good night time visibility is a safety feature and there is no doubt that these kits will improve your picture of the road ahead when driving at night. If they can do so without dazzling other road users and they are within respectable colour limits (i.e. not boy racer blue!), then I see no reason why they shouldn't be able to be fitted to any car.
Cheers,
Mike