People who are on imp-dev probably should have github accounts and get added to the imp github users, if you aren't already. That way you will get notification about new issues, can edit the wiki and the bug tracker and all that. Currently, there is more discussion of proposed changes to IMP in the bug tracker than on this list, which is kind of nice (as the bug tracker provides an easier to navigate record).
To do this, create a github account and then email Ben or I with the account name.