My Gmail account goes down at least once a day though. But, then it's always done that. My .Mac account hasn't gone down though (and it's still up today).
Could be that there's just a quirk in some systems between your computer and Apple's. A week or so ago there was a problem with some of the flooding causing outages between people who's data went through the flood zones to get to Apple's servers.
I am getting irritated with the amount it is down during the times I use it. I really don't trust its consistency to get done what I need. For example, right now, I can't read my mail, it just says loading.