Well if money didn't matter you would just buy the 3DS XL straight up. Trading in your Vita for it is a bad decision. Here's why:
1. You already have a 3DS. I know the XL is very tempting but unnecessary at the moment. You should try to find a place that will transfer your stuff over and trade your current 3DS instead.
2. You lose access to all Vita games. Though that might not mean much right now for you, later this year, next year, and beyond that, you are going to want to play those games too. You will probably end up buying a Vita again, so it is going to be expensive. Keep both systems, save your wallet for games.
3. Vita's future functionality is too appealing. You said it yourself, the Vita does things that Nintendon't (had too). PS Mobile will be hella awesome and make the Vita vastly more attractive outside of games, or in small mobile games if you like that, then the 3DS will. I'm talking tons of apps that go neck to neck with iOS and Android. Also Vita has a huge backlog of PSP games, minis, and will be getting PS1 games by at least next month (end of summer).
Basically, your impatience will cost you money. If you don't have 200 to spend right now for a new model of a system you already own, you won't have it down the road when you're kicking yourself for not having a Vita.
You will get a 3DS XL eventually or find a way to trade your 3DS up but do you really want to drop the money on a Vita again?
Before the PS3 everyone was nice to me :(
