Hey Pie. According to Kowen's graph the 3DS is doing on par with the DS, albeit in the DS' weaker stage.
One thing we know is that Europe is not traditionally Nintendo's region, it's more Sony's (and MS' in the UK). However, when it comes to handhelds Nintendo always dominates. Regarding the U, bro, I think the main problem is branding and marketing. If the Wii succeeded in the West, a lot of it was due to very accurate branding and brand image engineering. Imho this was failed for the U. There is very little buzz around the console and a lot of product confusion (what is it, why do I want it).
I'm not sure how Nintendo could fix this, but they need to inject a lot of money into marketting this console. However, to do that, they need the games to support it.
One game that was very big in Europe was Art Academy, others were Brain training and Nintendogs. Nintendo needs these games for the U AND needs to market them effectively to get the Wii success back. As for the core crowd, imho they're never going to get it until they lead the market themselves with 1st party IPs.
HTH 
