This is my situation, I have a website which has been online for a few years. It has PR7 and millions of visits monthly.
Since the beginning, I've always use the domain without www, users are used to it, most backlinks are to that domain without www... It is performing very well in SERP, standing #1 for most of its main keywords. Search engine traffic accounts for almost 50% of total traffic.
In short, it is performing very well with it current setup in terms of SERP, user loyalty and brand name.
There is one problem. Users to my site are from all over the world, from the US to Asia to Australia. My server is currently in the US, and its latency and network performance from other locations like Asia is very poor (300ms something, plus dropped packets and congestion sometime). I really want to improve the user experience and for the last month I've tried and benchmarked various networks, webhosting providers and services to find the best location for my server.
I ended up with Google App Engine, which is stable, affordable with excellent geo-distribution technology that make my site fast anywhere in the world (or at least at 3 locations with 95%+ of my users: US, Asia and Australia). The only problem with GAE is that they don't support naked domain (without www or subdomain). Sound stupid isn't it? But that's the way it is. If I was to migrate my site to GAE, I cannot keep the naked domain.
I've read alot of articles regarding this and most of them said it is OK to add/remove the www as long as proper redirection is used. There is even an option in Google Webmaster Center to select the domain with/without www. But I would like to have comments from experts and those who actually did this before putting thousands of dollars migrating the site and end up losing traffic. Yes I could try adding the www on the current server before the migration, but it is still a scary thing to do.
Please give me some advise