"It's a beauty for sure."
I agree.
"Is there still a train station attached?"
Yes, along with a shopping complex which was built in the late 1980s to replace the original station.
http://www.towercitycenter.com There isn't intracity train service (aka Amtrak) but the station is the main downtown transit hub (1 heavy rail line, 2 light-rail lines):
photo by rob_1412:
"Does the building attract office tenants?"
Yes, though the building's small floorplates aren't considered ideal, there are still numerous companies located in the Terminal Tower. The main tenant is Forest City Enterprises
http://www.forestcity.net/. In addition to the Terminal Tower (and adjacent Tower City Center complex), they're the developers of the New York Times Tower, Beekman Tower in lower Manhattan, Atlantic Yards in Brooklyn, etc.
Has it been upgraded for current office needs?
I believe so - I know that Forest City has put a lot of money into renovations. I can find out more info if you're interested.
Is it destined to be hotel and condos? What's the skinny?
I'm going to say not likely, but that would be one amazing place to live/stay, wouldn't it?