made some release notes 'splash' changes

[Luis Villa <luis villa gmail com>]

I made a bunch of changes last night to:
http://gnome.org/start/[insert latest version here]

If someone could proof/comment, I'd appreciate it. The goal was to put
the most interesting stuff (release notes, getting gnome) first, and
to clarify the language around each thing. The whole 'here is a bunch
of links, then a blockquote describing what you've just gotten links
for' thing seemed broken, so I fixed that. Let me know what you
think...

Luis