Well I would say if you have the coin buy it now as it is a great system. The library is strong with lots of RPG, Nintendo favorites, and interesting eShop Indy titles.....If you live in the US then you can catch them on sale at major retailers every few weeks. I see XL going for $179 at Target, Walmart, Miejers a few times a month so just watch the flyers....if you are not in the US then who knows. With the roll it is on I don't think you will see a major price drop soon, even though Vita just went to $199 in the US I think Nintendo will just op to counter with more bundles which can sometimes be a good deal. Maybe we will see the non-XL drop a little sooner if its sales start to lag but suprisingly it is still selling strong. I have owned both 3DS and XL and actually find pros/cons on both units but overall if I could only have one would want an XL at this point as the screen is just huge and even DS games look great on it. I am not a huge fan of the 3D effect as it will just make your eyes bleed if you use it too much....I mean it is cool and sometimes what I will do is switch it on for the cut scenes and then play the game with it off. Given its relatively limited horsepower and not that high of resolution some games look really good. I think the analogue stick on it is excellent and still prefer it over the Vitas sticks. If you like RPGs you couldn't own a better system right now with great games like Etrian Oddessy, 3 SMT games, Fire Emblem, Tales of the Abyss, Kingdom Hearts. Also a great system for platformers as all Nintendo systems are with 2 excellent mario games, Donkey Kong, and the new Castlevania, and Cave Sory 3D.
I hope that helps and honestly it is a great handheld experience and I like the clamshell design Nintendo has used since the GBA SP because it is just a more durable and portable design. I also own a Vita and it is a nice system and is getting more great games by the month. If you want a more 'console' like experience then go with a Vita once the price drop kicks in. It also has a lot of good indy games and you also can get a lot of good PSP and PS1 games from PSN. Also the Vita is a much stronger media player as you can buy a lot of movies, sports events, and tv shows off PSN. You can get netflix on both systems, but one thing that has dissapointed is that Nintendo hasn't made more arrangements to bring 3D movies to the 3DS as that would be cool.