Nintendo will make it something more casual-friendly. 3DS might start to sound a bit technical.

isn't the DSXL the final DS? i think the 3DS will be the real DS successor

3DS makes sense if the whole purpose behind the 3DS is 3D. But, I don't think that will be it at all. So, I think the name will be whatever best defines the features of the new DS.

The title works as an excellent play for a variety of possible releases, so I kinda hope it is going to be the name.

As for the whole "temporary" status of the title, that's the key word - TEMPORARY. It's not a CODENAME, like Dolphin or Revolution. It's a TEMPORARY name. Temp names can, and often do, end up becoming the official title.

I hope this new handheld is as good as it sounds.

I can see why it would be a good final name, I actually quite like it. I'm sure if Ninty do intend to change the name it will be something equally good, perhaps as controversial as when 'Wii' was first revealed.