I think this is a great idea, especially the part about native
installers. You can put me down as an interested party.
An install program could make the package size much smaller by using
pack200 or other compression techniques, and help eliminate one of the
complaints often heard about Eclipse (it's too big).
Also an install program could look to see what JRE you have, make sure
it's a good enough version, and add VM specific options, for example to
increase the max permgen size.
It could also do things like set up file associations to support
double-clicking on a file in the Explorer/Finder and tickling Eclipse to
open that file (starting Eclipse if necessary). And it could set update
sites and auto-update policies.
Another thing you could do is create an installer for "The Eclipse Rich
Client Platform" that could be reused by all Eclipse-based applications,
including the IDE. We do that at SAS to avoid re-shipping those bits in
every product. It works kind of like the Microsoft .NET Framework
installer. (A .NET program requires a certain version of the Framework
to be installed first, and thus every .NET program doesn't have to
include the Framework.) Programs and frameworks can also be distributed
on different schedules if you're careful about backwards compatibility
or can do side-by-side installs.