I'm relatively new to drupal, but I'm enthusiastic about what I see so far... except for a strong concern over unacceptable slowness.
I see that this issue has been raised before, eg: Nov 22nd, but it is still a problem.
To reiterate: If drupal.org is slow, it:
a) Gives the impression that drupal software is unacceptably slow
b) Makes pages on drupal.org impractical to use as for learning about drupal, for reference, or for keeping up-to-date on developments.
Ignoring that there's a problem implies that this is as good as it gets. I see that there are some Handbook articles on performance (though "Case Studies:Big Drupal Sites" goes nowhere..), but if even drupal.org isn't successfully implementing these, what are we to think? If there's no funding to fix the problem, then one compensation would be to at least characterize it -- "yes, it's slow, but this is unrepresentative because X, Y and Z".
Some figures. These are representative, over several days, day or night (night maybe slightly faster, but still slow), two different locations in San Diego CA (drupal.org appears to be hosted in Oregon, our neighbor, right?), two quite different ISPs (cable and DSL), IE and Firefox on Windows, and Firefox on linux.
Main page 3-5 sec
/project 2-6 sec
/project/Modules < 2-6 sec
/project/Modules/name 10-15 sec [*]
/forum 3-8 sec [*]