1. Servers ARE still up. But it depends on when you play and where you are. It is 100% random though even under best circumstances, and since you need 4 players. So for all intensive purposes, it is dead. A note too: I have not updated my Vita in quite some time. When I played 2048, I didn't need any update to connect. I am in the US, so I don't know if this was luck or coincidental. I recognized no one online.

2. If you are into the Wipeout canon as far as the storyline progression goes, it is worth picking up. On the off chance that you might actually want to play online, you need to try to find a new copy because it comes with an unlock code to play multiplayer. If you buy it used, the code may have already been used or not be there at all. In my personal opinion, if you are a fan of the series, it is a must own just for collections sake. The controls are sub par, the grid mode is awful, the framerate is variable at best, the online selection mode is Satan, and the best part of the game is the free HD/Fury DLC if you own WOHD on PS3. You can connect and play with other people on PS3 playing WOHD, but you'll be at a disadvantage because of framerate and control issues. If you are after trophies at all, achieving 100% is nearly impossible without boosting because there are two gold trophies for completing the online mode and for completing every grid of online mode. For that you need 3 other people to play through about 4 hours of tedious races.

3. Ad hoc mode is confirmed, but in the US, we can only get Pulse on the Vita. Some regional restrictions may apply. As wiggle pointed out, the single player mode is an excellent bargain, and is more fun IMO than 2048.

4. OMG the framerates are better. But I know nothing about any upscaling.