Scanning through the NHL's press release about "signature events" over on Kuklas Korner, it seems the NHL has tipped it's hand for the 2010-11 season opener (emphasis added by me).
In the U.S., the season begins with a special doubleheader on VERSUS. Both Stanley Cup finalists will take to the ice when the Flyers play Pittsburgh, followed by the Blackhawks squaring off against the Colorado Avalanche.
It's possible, of course that Flyers/Pens COULD be in Philadelphia, but it makes sense the NHL would showcase Pittsburgh's new building and allow it to host it's first game on opening night. Certainly a matchup against the Pens' biggest rival would make for an appropriate first game in the new barn.
The complete schedule will be released on June 22nd. The only thing we know for sure is that the Penguins will again have New Year's Day plans.
UPDATE:
It appears this is in fact true, and the Flyers will be the first regular season vistors to the Consol Energy Center on Thursday October 7th. The Penguins are going to play a few exhibition contests in the new arena to break it in, though.