To put it mildly, the PlayStation Vita has struggled since it was introduced, but recently after a price cut in Japan the sales of the unit have surged. The 3G model has been reduced from $299 to $199 and the bundle includes an 8GB memory card; and if you sign up for the 3G contract in the store where you buy it, you also apparently get a free PSN game for the unit.
It is hard to say what Sony might be up to here without official confirmation from company; but it would seem that retailers we have spoken with think that the price cut is just a way to move the inventory out before it is discontinued in favor of just the offering the Wi-Fi only unit. Of course, if the response to the price cut is strong, we could see Sony also considering a price cut on the Wi-Fi only unit to help the stagnant sales of the unit.
Joystiq has more here.