Trademarks really came to light last year as a source of spoiler information, with the only real whiff being the confusion over the set names for the Scars of Mirrodin Block. MTGSalvation poster 'Guinea Pig' posted the appearance of three interesting trademarks:

1. Elspeth Tirel
2. Duel Decks: Ajani vs Nicol Bolas
3. Magic: The Gathering - Commander

The nature of a registration at the US Patent & Trademark Office is that you must intend to actually use the Trademark, we can safely interpret the first two, but the third one is still up for interpretation. 'Elspeth Tirel' signals a return to the trademarking of Planeswalker names (as noted in the original post), protecting them from use in other mediums and games. 'Duel Decks: Ajani vs Nicol Bolas' seems to be the second Duels Deck of 2011. Perhaps this is where we'll see a non-foil version of the Pro Tour Promo for next year.

The curious one is 'Magic: The Gathering - Commander.' Commander is of course the MTGO name for EDH, so why would they be registering this trademark? Is it to push EDH as their next casual format, following Planechase and Archenemy? Or is it some other product all together? Only Wizards knows and time will tell.