It's difficult because the major updates typically change some world generation algorithms or something, so users won't have access to some features that would only generate and be available on a new map.
We were on the last map for quite some time, and I think it's entirely appropriate to move to a new map as we just updated through many versions.
We'll consider user input, but the plans are to settle on a map as soon as the plugins are up to date. Until then, expect a new map if the version update consists of major content addition, bug fixes in world generation, etc... (basically big updates like 1.0, and 1.3).
EDIT: I just spoke to Kodlee, the plan is to run 1.4.6 with Bukkit. As of right now, we're running 1.4.6 with all plugins operational. Fresh map. Cheers!