evaluating gui modules, any experience on tkinter?

[krishnakant Mane]

hello all,
I seam to have noticed this a bit late but it appears to me that
tkinter is being used very widely for gui development on all platform?
is that right?
since fredric lundh has written a very good introduction to tkinter
(was that just an intro?), I have got keen interest to know the
following.  may be fredric himself might put some light on these
points.
1. I seriously don't intend to start a flame war but does tkinter
stand up to the standards of heavy gui development?  can I have an
entire mdi application working fine with tkinter?  I know wxpython can
do it and I have heard enough about pyqt, but tkinter seams to be very
rich in gui objects.
2.  as usual I always look out for accessibility when it comes to gui
design.  will tkinter be useful for blind people?  I mean, are gui
apps in tkinter accessible on windows?
3.  I don't know if I need any thing else as dependencies on my
windows machine.  I am using python24 and I did not find any thing
about installation in the introduction to tkinter.  can some one give
me the process of installing tkinter and all necessary things?
4. is tkinter absolutely compatible with windows gui?  does it call on
native api for native look and feel?  in that case I think
accessibility issue is automatically solved.
I am looking out gui library for some serious application development.
 one is an erp system and the other is a customer relation management
system.
so I am confused between wxpython pyqt and now tkinter.
out of the 3 I only found qt talking extencively about accessibility,
but did not find a way to install qt in the first place.  I could not
compile qt nor did I find any run-time dlls for mingw so that I can
use it out of the box.
wxpython is the poorest in documentation and tkinter seams to be best at that.
please give me some advice.
thanking all.
Krishnakant.