Despite the persistent & malevolent comments of some gentlemen-on CCC forum- against Vasik Rajlich and Rybka-the contemporan computer chess is in big progress.The fantastic strength of Rybka 3 and its strong & various analysis capabilities (IDea,Monte Carlo,shared analysis.....) generated a polarization in computer chess GUIs. WE HAVE TODAY ONLY TWO TRUE & COMPLETE PROFESSIONAL GUIs:
-ChessBase 11 for Rybka & Fritz;
-Aquarium.
Only these GUIs offer a total support for Rybka 3 ( nice to see ChessBase adding support for the UCI protocol ).
In this situation will be a real market/interest for Shredder & Chess Partner GUIs or any professional interest for Arena GUI ?
Vas will make available extensions UCI to other engines and GUI can add it. Of course I do find it interesting that add new possibilities for analysis and new options in GUI and engines. Users will tell whether these tools are interesting or not.
But I believe that the specifications of these extensions should be ready and already published since the day that Rybka has come on the market and that interfaces like Fritz and Aquarium incorporate it. I think this can be regarded as unfair competition, please note that Rybka uses a protocol that is open, although I have not seen any developer so far has been complained about it.
And that the two interfaces have these options that you say, do not become the only two, depends on the things you want done. The two interfaces that you said have a bad support for winboard engines, for example.