So, Why didn't this become a new lease of life for the TC line? from a dev point of view its life would have been vastly improved. I know there was the cost of buying COD for this, but server admins could have turned off cd key check and clients could connect with 'cracked' install with out issues, just like back in the q3 days.

I bought CoD4 for this. Still, it payed off on the game itself.

As far as development goes, keep in mind we've been waiting for unlocked CQB for a year now. :)

Sooo.... when is coroner releasing TC:E 0.50?

It's useless banging the head against the wall.
"pacta sunt servanda" it's a basic principle ... nothing more, nothing less.

I thought MWTC was generally disliked and nobody played

There was quite some community effort started to convert maps. COD4 engine has many advantages including the COD4 radiant.

Are there any MWTC maps beside "backlot" and "hangar" around today? I'd like to test some of these...

I think the only real downside at the time was players would have to buy legit copy of mw, Personally i liked it and it was not hard at all to port maps from tc to cod, but i think tc:cqb is where the future is.

I am intrigued with this, what if I will give a try anyway nothing wont matters to do a try.