I'd happily buy a Mad Archives Volume 5, especially if it went to say #29 or #30 just to round things out and provide a taste of the Feldstein era. Beyond #30 I'd be just as content to pull out my cd-rom of  Totally Mad and leave it at that. But having V. 4 come out so soon after V. 3 is grand news indeed! Now I can finally have that Color Mad set to go along with my EC Library B/W set. What, Me Worry?????