Neil Clarke, publisher and editor of Clarkesworld Magazine has put up this interesting website/blog about the current rule change under consideration to eliminate the Semiprozine category from the Hugo Awards. Says Mr. Clarke:

This is a website born from an ongoing attempt to abolish the Best Semiprozine Hugo. In the course of trying to eliminate the category, some disparaging remarks have been made against semiprozines. By and large, I consider their statements about the worth and health of the semiprozine field uninformed. As such, I have invited (and continue to invite) the people involved with these publications to join me in providing content for this blog.

Our goal is to be both educational and informational. We’ll be featuring specific venues, providing current news, and offering some of our opinions on the state of the field as well as the Best Semiprozine Hugo.

At this link, the website lists some of the semiprozines (with links) that would be eliminated from consideration for Hugo awards. The web site will review the publications as a whole in time. Clearly, there are some fine publications in the list. I've reproduced the list below, minus the links. Mr. Clarke said that this list was compiled from 2007 and 2008 nominees for the Hugo.

• Abyss & Apex
• Ansible
• Albedo One
• Apex Magazine
• Andromeda Spaceways Inflight Magazine
• Baen’s Universe
• Clarkesworld Magazine
• Fantasy Magazine
• Futurismic
• Greatest Uncommon Denominator
• HUB Magazine
• Interzone
• Internet Review of Science Fiction
• Lady Churchill’s Rosebud Wristlet
• Locus Magazine
• Neo-Opsis
• New York Review of Science Fiction
• On Spec
• Orson Scott Card’s Intergalactic Medicine Show
• Postscripts
• Shimmer
• Strange Horizons
• Talebones
• Tales of the Unanticipated
• Weird Tales

From Science Fiction Awards Watch (where I learned of this issue) is this description of the rule change (and other changes to the rules):

Removal of Semiprozine Category

A proposal to remove the Semiprozine Hugo was passed and forwarded to Montreal for ratification. The old qualification criteria from semiprozine are now used to define what is not eligible to be a fanzine. (We’ll post the actual wording later when we get official electronic copy). The vote was 40-28, and the issue continues to be hotly debated.