Harold - sponsorship or advertising seems reasonable to me and I don't think it's a problem at all. As long as you don't spam us with ads.

Likely, there are sponsors out there and even more likely they would like to get in front of the various bloggers who cover topics related to training and eLearning. That's part of the reason that Learn.com was kind enough to sponsor a blogger bash at the eLearningGuild Annual Gathering.

If a sponsor has an interesting opinion or something to say that bloggers would want to talk about, then this avenue is even better.

Best of luck with this pursuit.