I agree it sounds like ABS ECU. My car went the same way. It worked Ok first thing for progressively shorter periods of time till the speedo, ABS, TC and cruise control functionality stopped altogether. I cleaned all the sensors up, changed bulbs and so on as per suggestions in the vain hope it would sort it.
One small concern I have is that the power steering continued working fine on my car. There are however an astonishing amount of wires going into the unit via a large plug and a few via a small plug underneath so the power steering may be affected by a faulty unit.
If you decide to do the job yourself then PM me your Email address and I'll send you some photos i took which would be helpful.
-specific tools I found helpful
-What the detached unit looks like
-What the pink retaing clip looks like
-how much beer to get in
One day I will attach them to the Maintenance guide when I figure out posting photos! There is some good info on this forum if you do a search.
varche