I don't live in Portland so I'm a bit ignorant of the city's stadium issues, so forgive me if this is a stupid question, but why does the Coliseum still exist? Does Paul Allen own it as well? What are the future plans for the site?

Recent chatter about the Penguins moving to Portland raises the question for me, because like the Blazers recently found out, it's hard for a sports franchise to make money without its own stadium. I suppose the Penguins could share the Rose Garden, but if it's Paul's stadium would they get any revenue from the ticket sales? Could any other sports franchise, for that matter, survive in Portland without its own building? Seems like the Coliseum occupies prime real estate that could be used to lure teams that want to build a new arena--like the Penguins, or or the Raiders, or the Florida Marlins (how about the Portland Sturgeon?). Does anyone see this as a future possibility for Portland?