Today show anchor Matt Lauer announced this morning that former Today show, and current CBS Evening News anchor, Katie Couric, will be back on the program tomorrow morning to make a, “major announcement.”

“Permanently?” asked anchor Meredith Vieira. Lauer laughed: “No, you’re not sick again tomorrow are you?”

Let the speculation begin.

TVNewser has calls in to both CBS and NBC regarding what the announcement could mean.

> Update: An anonymous tipster writes, “Wednesday’s announcement: NBC, CBS and ABC are teaming up for a joint telethon. Cancer research. Couric, Williams, Gibson, and others. September. On a Friday night.” But why would Couric go on Today rather than CBS’ The Early Show?

Click continued to see Lauer make the full announcement announcement…