I'd be interested in hearing what steps you have taken in the last two months to resolve this issue with webmail and teh web panel. You mention proactive steps, but aside from the fact that they are in fact REactive (the problem already exists) nothing seems to have been done.
Over the year and a half I've hosted my domains with Dreamhost I've been through a number of issues. However, the one constant seems to be INTOLERABLY slow responses from Dreamhosts various applications, and no matter how many supprt requests or complaints i submit nothing is done.
Recently I submitted another support request regarding webmail being ridiculously slow. I mean it is essentially akin to being on 28.8 dial-up, and I'm talking about using it over a lightning fast T1 or cable connection (my current connection gets about 1.8mbps down). On top of this the web panel is also just FRIGHTFULLY slow... it takes me ages to do maintenance just because I have to wait for the damned pages to change and save my settings.
Yes, I am on the east coast, and I have to go across the country through various hops to get to the DH servers. However, this is just ridiculous and I don't see these kind of delays accessing sites around the globe, ONLY with Dreamhost.
I've recently started to look for other providers specifically because of this problem, so I would recommend you take immediate steps to rectify it. Hell, even customer support now seems to be infected with this DH time dilation... my current support request has been open for 21 hours with NO response.
I gotta say DH is definitely looking less attractive.