The Grandpappy of software companies has a big announcement today and the consensus seems to be that it’s all about tablets, probably some sort of joint project with HP. TechCrunch says it’s a tablet alright but will be a joint project between Microsoft and Barnes & Noble and it will be an e-reader with a lot of Xbox capabilities. The event happens in Los Angeles, TechCrunch notes, and if it was just a tablet, why would the announcement be held in the entertainment capital of the country?

Anyway, it all happens at 3:30 pm Pacific, 5:30 Central time. “We really wanted to mess with all the Marketplace deadlines,” said a surprisingly vindictive Microsoft spokesperson except not really.

Computerworld digs up an SEC filing for some clues:

In an April 30 filing with the U.S. Securities & Exchange Commission, Barnes & Noble noted that Microsoft might create something called “Microsoft Reader,” and if it did, pledged that the device or software — it wasn’t clear which Reader would be — could access the new digital content market NewCo would build.
“If Microsoft creates a reader, Microsoft may include an interface to the NewCo Store in that reader and may surface in that reader all Content purchased by customers from the NewCo Store,” the filing stated.