I was catching up on some of the TTLG forums earlier this year and I caught a thread discussing where Thief was going before Looking Glass went under.

Apparently, there was talk of making Thief 4 take place present day (under the impression that they had done enough with the steampunk fantasy genre). There was even some concept art done (sorry for no link) of a catburgler/hoodiewearing Garrett.

At first I scoffed at it, hipping it up for the youngins and console gamers, but then I started warming to the idea... guns instead of bows, possible magic/technology uses. It might be tricky, but Thief 1 and 2 were good enough that if they kept most of the original team, I'd give the idea a chance.