The new slimmer Vita-2000 model is coming to the US this spring. It'll debut in a new Borderlands 2 Limited Edition Vita Bundle which includes the system, the game, six DLC packs, and an 8GB PS Vita memory card.
As previously explained, the new Vita model is 15% lighter, 20% slimmer, and includes 1GB of built-in storage. Controversially, it drops 3G connectivity and replaces the system's original OLED screen with an LCD. However, the revisions allow the Vita to gain an extra hour of gameplay time on a single charge. You can see all the changes in a new sizzle video from Sony: