As noted in our Call for Papers (CFP), Doug Lea and I are co-guest-editing six special issues of IEEE Internet Computing this year on the general topic of middleware.
Unfortunately, when we issued our CFP, we didn't make our deadlines terribly clear. We hoped to get all submissions in by May, giving us time to work with the authors of selected submissions to get them into shape for publication over the course of the year, so we put May as the deadline. In reality, we have deadlines that are generally about two months prior to each issue's publication. It now seems that everyone is just waiting for the May deadline to get something to us, which admittedly has left us scrambling a bit for the upcoming May/June issue.
If you're planning to submit something, please do so anytime, starting now! If you'd like to submit something but don't think you can meet the May deadline, email me or Doug (or both) and let us know what topic you're thinking of writing about and when you can get your submission to us. We'll be happy to work with you.