I like the games the system offers but I do not see any justification for the price of the system itself. The DS was over 100€ cheaper than that.
The competitor the 3DS must beat is not the PSP. It is not the iPhone either. It is the DS. How much more does the 3DS offer to me, the customer, that would warrant a 100€ price increase? This question gets much, MUCH worse once you ask it from the perspective of the blue ocean crowd the DS brought in. How much would glasses-free 3D improve games that are not 3D in the first place?
Sony had a similar problem trying to migrate their Buzz and Singstar audiences to the PS3, there is no real benefit from going to the bigger hardware as the games were never hardware-constrained anyway.