The tricky thing is that the cover, shown here, is a limited edition (“variant,” as we say in the biz), with the normal, much more common one being much less Obama-y. As you could expect, that means that version of the comic (both were just released today) has already become a collectors' item, selling out all over the country.
I went to Comics Toons N Toys in Tustin–the best comic shop in OC and one of the best I've ever been to, in this well-traveled geek's opinion–this morning at 11:30 a.m., just a half-hour after they open on Wednesdays (the day new comics are out each week, of course). They had already put out a sign on their door saying that they were out of the Obama cover, and letting people know that a second printing would be out soon. Since Comics Toons N Toys is usually great at ordering plenty of copies (they're a great place to check if you can't find something), this is surely the case throughout the area. The second printing looks just about the same (it's the same drawing by artist Phil Jimenez) except for a different colored background, and is being rushed to stores ASAP.
Don't count on either edition, even the first printing, on being some sort of long-term investment, though: that almost never works out. Superman #75, the 1992 comic where Superman “died,” was once the hottest comic in the world and I think now is used as currency in some third world villages.