Thing is, at the time the DS hadn't 'taken off' like it has done now. At the time it had the largest pre-orders of ANY DS game before it (something like ~270,000, selling ~250,000 in its first week). This was thought to be spectacular at the time, because most DS games were hitting around 20,000-30,000 in their first week MAXIMUM, then disappearing into the aether...
So it all becomes relative. Looking at how the DS reportedly sold nearly a 1/4 million Lite units this week (!!!), and thinking about how many of those buyers are anime fans...the potential is amazing. Just look at how Tetris, something as damn simple as Tetris online, is well on-track for reaching a million sales. Two weeks and it already looks like having the legs to make a million...that's damn scary.
Ganbarion, the developer of this, did a superb job the first time round, and with more time to pour into this version (I still haven't seen anywhere else say it's online...so I'm worried about mis-translations...let's hope not!) it should be bloody amazing. And with more and more new anime shows coming to the US each month, by the time this hits (in Winter, missed that out, sorry!) it should be ready to 'test the water' in the US.