Yes, I've been seeing some slow/odd behavior from Gmail/google in the last few days.
I have a Droid (unrooted) and a Nexus One, both linked to the same gmail account. When I got the Nexus, a couple weeks ago, email would arrive on both devices nearly simultaneously and then on my desktop a minute or two later.
Delete an email from one device and it's gone from the other within in a minute.
Starting sometime last week, there's been about a 5 minute delay between email landing on both devices and often emails will arrive on my desktop well before they ever hit my phones - 10 or more minutes.
Probably unrelated, but gmail and igoogle are nearly inaccessible from my work computer (with firefox 3.6) since about the same time. Gmail just won't load period, I have to use Thunderbird (3.0.3). igoogle is usually ok, but I have to refresh the page about 5 times before it actually shows up.
No major changes to our work network. Been using Firefox for...a long time.
I'm still getting email and there's not a massive delay, so it's ok for now. Just a little annoying. Did read this morning that other corporate/government users with Firefox 3.6 are having gmail issues.