Promoting a huge number of »different playable classes« is one of the most mis-used and deceiving proclamations in the realm of MMORPGs. Seriously, what does it really matter, if a game has 30 different classes to choose from if the only thing that sets each class apart is e.g. one single talent or backstory twist.
I'd prefer keeping it bold and simple, with only a few classes to choose from, as long as these classes are perfected and solid. Besides, if all things go as planned, I'll only be experiencing one of these classes post-launch and hopefully in quite some time thereafter.