Arenas out for 6 months?

According to an article on Basketball Prospectus by Kevin Pelton and Will Carroll, yes, that seems to be the consensus of the article. I'll quote directly from the piece, but you should really go read it.

"The three-month recovery quoted by the Wizards is extremely aggressive--most physicians interviewed for this piece felt that six months was a more likely scenario--but none would rule it out. "Pain tolerance is what it will come down to," said one orthopaedist who regularly performs this type of surgery on skiers."

The rest of the article speaks to the future problem Arenas will most likely have. Whereas he was practically assured of getting a max deal from the Wizards or elsewhere when he announced he would opt-out, now that doesn't seem so guaranteed. His knee may have never healed completely, evidenced by the return of swelling when he pushed it.

The article goes on to discuss the fantastic contributions of AD and Blatche (to which every Wizards fan should remark, "well, no s**t, we knew they were good"). I'll end this with one other direct quote from the article, one that speaks differently of their defense than I have in the past.

"Butler and Jamison have been brilliant since Arenas' injury, averaging 24.3 and 29.0 points, respectively. More striking has been their efficiency. Butler has hit 11 three-pointers at a 64.7% clip and has a 65.7% True Shooting Percentage; Jamison is hitting 56.3% from the field and has a True Shooting Percentage just behind Butler's at 64.5%. Last year, their True Shooting Percentages were 53.7% and 54.5%, respectively, and both players will have a very tough time maintaining their efficiency. As they cool down, so too will the unsustainably-hot Wizards offense."