1. The jihadi chants in the background make no mention of "Osama bin Laden," "Abu Abdullah," or "al-Emir," three titles associated with bin Laden. Indeed, there isn't any mention of "kufr" (infidels) and the talk of jihad comes at the very end of the chant. Nor is there any mention of the word "shaheed" (martyr), which a tribute to bin Laden would certainly include.
2. I'm not entirely certain, but I don't believe that bin Laden's bald, as this individual certainly is. Anybody see any pictures of bin Laden without his turban on?
3. This looks a lot different from the bin Laden we saw in the last video. If this is supposedly from Tora Bora in December 2001, he should look considerable worse, not better.
4. If bin Laden is dead, it is highly likely that he was killed during the American bombing. This guy seems to have died from a gunshot wound.
5. The nose looks considerably smaller than bin Laden's.
Additionally, the background of the footage doesn't look like Afghanistan in the winter. The website looks like it's a legitimate member of the al-Qaeda fan club, but I'd wait for a translation before jumping to conclusions. According to one of the threads linked, the site is based out of the Philippines. Perhaps its owners have connections to the Filippino al-Qaeda (Abu Sayyaf or the Moro Islamic Liberation Front)?