iPad watch out: Samsung is gunning to take over the tablet market. The company announced during a press conference late Thursday that the recently announced Galaxy Tab would be launching on all four major US cellular networks—Verizon, Sprint, AT&T, and T-Mobile—and a WiFi-only option will be available soon. There won't be any 4G-capable devices at launch, however (only 3G), and Samsung is remaining mum on pricing.