I think if you ring up they will still give you one, not sure tbh. But the router i got when i was on 10Mb (as it was at the time) was sub-par IMO.
Always best to call up and ask
As for the new 50Mb modems, yes, they will be pretty different, but i honestly doubt they will include an inbuilt router, as this would more than likely anger a few customers who have advanced home network setups. (Can you imagine all the port issues with it?)