I checked in late August and all the B5 allocations were already taken then for the 2010 production even back then. The production ended sometime around mid to late October.
Many 2010 B5's have been getting delivered to dealerships in the last couple months though, if you search around you may be able to find one pretty much exactly like you would have ordered at a dealership somewhere.
The dealer near me has 3 B5 classics and 2 B5 SRT8's sitting on their lot right now. I don't want to give the dealers name because they mark their Challengers up 3K over sticker. But many other dealers have them now so if you look around you should be able to find one for a good price at one of them.