[UPDATE: Apparently producer Al Gough has changed his mind and wants Smallville to go 8 seasons.]
"Yeah, we’re finishing up our sixth year and next year is the last year."
Sounds like confirmation to me. Of course I reported that Smallville would only go seven seasons a year and a half ago. :-)
The show's ratings are strong and it's as popular as ever. I think it's great that they'll be going into next season KNOWING it's the last one. That way they can map out a season-long arc that will hopefully flow really well and give a fantastic close to the series. It should be the culmination of the the Clark/Lex relationship, finally bringing Lex completely to the dark side:
"...next year is going to be the biggest year of all; it’s the final year and everyone’s going to see what Lex Luther is really capable of. All hell’s going to break loose!"
I know that there are a lot of fans who would like the series to go on and on, but I hope the producers stick to their guns and end the show while it's on top. There's nothing worse than watching a great show stick around a season or two too long.