The European store has only just opened, and at the moment there isn't really a lot to get excited about. The free Web browser, based on Opera, is surprisingly usable and functional, but game-wise we're limited to a range of very, very simple puzzle and arcade games and one, sole 'keystone' release, WarioWare Snapped. The latter, which features camera controls similar to a cut-down EyeToy game, is an interesting experiment, but the controls aren't particularly effective and the impression is of a game that's high on novelty value, but low on long-term appeal. This isn't a disaster given that all these games are cheap (even WarioWare Snapped is 500 Wii points, or less than £5), but at the moment it's difficult to get a real feel for the DSi experience, as Nintendo envisages it.
That's why it's hard to come up with a definitive verdict on the DSi at this stage. At this exact moment, it's hard to justify upgrading from a DS to a DSi or buying a DSi instead of a DS just to mess around with some low-resolution images, particularly given the £50 difference in price. It's also unlikely that Nintendo will move its biggest hitters - Brain Training, Mario, Zelda - to the DSi and risk alienating the huge existing DS userbase. DSi owners will get enhanced versions of the DS games, but whether these enhancements will be major or minor it's impossible to say at this stage of the game. Finally, it's worth remembering that the £150 price point puts it in contention with Apple's iPod touch. While the DS still has the better games overall, the touch/iPhone platform now has a handful of excellent titles, a wider range of alternative apps, better audio and video features plus support from industry heavyweights like Electronic Arts and Konami. This just can't be ignored.
Given these things, it's tempting to write off the DSi. However, in six months time Nintendo might just release something that makes the DSi feel utterly essential, and me feel silly for ever doubting it. The new Zelda or a new Mario game might appear with features that will make the DS version feel like half the experience, or something of the quality of LostWinds or World of Goo might appear in the DSi shop. Personally, I'd hold off for now until that happens, but if you want a new handheld and feel like taking a small risk, then the DSi is a very interesting little beast indeed.
Right now, the DSi doesn't feel like an essential upgrade over the existing DS Lite, but with the cameras, the extra CPU horsepower and the DSi Shop, there's potential for that situation to change. Don't write it off.