Clash of the Titans was not meant to be in 3D until very soon before its release. One of the reasons that films like Alice in Wonderland and Clash of the Titans looked pretty poor in 3D was because the decision to convert them came very late in post production, due to the recent success of Avatar and the just-happened rush to get 3D content out. So, rather than being done right, they needed to be readied in half the time they normally have, the results being less than stellar as one would expect. 3D conversion is an expensive process for the simple reason that it is a very long process. The SW releases are being given the longest conversion time that any 2D film has ever been given, as far as I know, and therefore I would expect they would be the best 3D conversions ever seen.

Another reason stuff like Alice and Titans were not impressive was because the way the 3D was used--in order to emphasize the dimensionality, shots are given 3D effects that are way too exaggerated because the suits at the studio want to "wow" you with the maximum amount of 3Dness. Luckily, in the case of the SW releases a lot of the people working on them are critical of some 3D releases for that very reason and have actually stated that the 3D work will be restrained when it is appropriate, so that things look natural and not just "popping out of the screen."

So, IMO, there is every reason to suppose these releases will be of the highest quality. I for one am looking forward to them.