Yes, that's not a joke. Namco and Capcom are indeed pitting Tekken and Street Fighter characters together, announced about 10 minutes ago. Ono is having a conference at Comic Con right now where he announced this and Street Fighter Third Strike: Online Edition. Both these games will be hitting PS3 and 360 eventually. Also, Namco are developing their own version called Tekken vs Street Fighter.
I though this was weird enough to make a thread of it, yes. A liveblog is
here.
edit: And
pics!