I love the DS. It can't be beaten.
I fell in love with it just hearing about it from the japanese press release last January that mentioned oh-so-briefly that there would be a new handheld that had 2 screens. That's all they said.
When it was shown off at E3 however... Gods, I knew I had to have one.
NOTHING has gotten me this excited as I am over my DS. It REALLY helps that the DS I'll be getting by the end of next week is a special VIP one from NOE with a free Exclusive DS T-shirt, Super Mario 64 DS and a Demo version of Wario Ware Touched as well as the DS itself and Metroid Hunters. Oh, and a month before everyone else. ^^
I think the DS can be and IS the greatest thing to happen to Videogaming since the SNES. For the first time in over a decade, people are thinking about how to develop games again. Developers themselves have admitted they love the DS because it gives them a fresh challenge - something other than just "Press Button A to jump, Press Button B to fire and use the D-pad to flick through menus" or "Go to point A to get to Point B by going across the screen".
The DS can avoid the crappy ports that other systems get because even when porting over liscenced titles, you have to actually think about what you're doing to incorperate both screens, the touch factor and if you wish, the microphone. Spider-man 2 attempted this... not greatly it has to be said and it more than likely is a sign of things to come in liscenced games for the DS (But, it's no huge surprise, considering they're liscenced games), but it does show that they took at least a day or two to think.
Thinking is a process long forgotten in many game development companies - they simply churn out games for money these days, forgetting stuff like Gameplay in the process. A lot of developers are looking to the DS to try out new stuff and to actually put a new spin on gameplay.
That fact alone makes the DS one of the greatest systems EVER in the history of gaming as it has been faaaaar too long since companies other than Nintendo focused on Gamplay rather than what's "cool" or easily sold to guillable parents and grandparents.