it would be nice to be able to create a campaign 'group' for long term activities.
for example the marketing for our annual conference (a major activity for our business) starts 12 months before the event and is followed up monthly to different target areas. Similarly we would like to monitor the ongoing performance of our monthly newletter without having to record stats in an excel spreadsheet offline.
if a campaign could be assigned to one or more groups that would be even better as sometimes our newsletter might have a major piece on the annual conference which would be applicable to both groups.
the groups could then have a dedicated summary report giving some overall stats such as recipient count, open rates, click rates, etc that would exist for as long as the group existed even if we had deleted the specific campaign (to keep the campaign list tidy).
i know you can compare campaigns and get open and click rates over time, but this does mean you have to keep campaigns for as long as the period you need to examine (12 months in our case), but I think the comparison reporting could be exposed to clients much better with a grouping system.