Hi Soultaker,
I can empathize with your frustration. I will admit, creating apps using MCML is not for the faint of heart. Frankly, it's not designed for folks who prefer working with visual design tools such as the Expression apps for the .NET Framework 3.0 (aka Avalon / Windows Presentation Foundation). The Windows Media Center team has made a concious decision to focus on the fundamentals of the UI rendering and MCML itself rather than create a design tool. Personally, this creates frustration for me as well (like you, I'm used to using visual design tools, like Illustrator and Photoshop) -- but it's the right thing for us to do.
Also, we have been pretty clear from the beginning we were not publishing WYSIWYG design tools for MCML -- so hopefully you aren't surprised there aren't any. At the same time we have worked with the .NET Framework 3.0 team to put into place some modicum of support for XAML apps for use within Windows Media Center so you can leverage their great WYSIWYG tools.
Are there tradeoffs by choosing one or the other? Sure. Check out the 'Choosing a Technology' section of the SDK where we enumerate many of those (including design tools).
So, we hear and note your frustration, and hope you will stay the course with us -- your feedback is valuable.
Charlie Owen (Microsoft)