Installer boot screen lost "F5=1024x768" feature.  While it's ok with me to look
at 800x600 installer (1024x768 leads to small/unreadable view on 15"), the limit
has some consequences such as:

- fixating the FB resolution of _installed_ system at the same setting (not much
of a problem but still);
- somehow limiting the availability of higher resolutions in _default_ (not
extended) resolution list while setting up XFree86.

That is, I see only "640x480 800x600" cases until request "more resolutions".
I'm afraid that in non-expert mode, even larger screens like mine 21" would get
limited to these two resolutions which are traditionally HORRIBLE with X11 :(

1024x768 is somewhat sane default these days, though if installer would live at
800x600 *without* limiting the live system's X11 resolution -- it's just OK.