Some might think this news is all the more reason to question technorati's future. Technorati invents a microformat, gets it adopted, and then finds competitors eating its lunch. But the reality of it is that IceRocket's adoption of the reltag standard is the surest sign of success for at least some parts of technorati's strategy. Take into account these observations:

• Technorati currently tracks 13 million blogs.
• Let's say half of those are producing tags of some sort, making 6.5 million blogs tracked with tags. The tags can either be inferred using the categories from the blog's RSS feed or explicitly embedded in the posts using reltag. The estimate of 6.5 million comes from the fact that over half of all blogs are capable of at least producing categories, making them de facto taggers.
• Kevin Marks, technorati's crawler guru, tells me that on the order of 15% to 20% of tags are currently culled using reltag with the rest coming from RSS categories.
• Running this estimate against 6.5 million total taggers suggest that on the order of 1 to 1.3 million blogs are serious enough about tagging to explicitly use the microformat.

• Blog post tagging is significant, with over a million explicit taggers to back that conclusion up.
• The reltag microformat is a runaway success, based on the analysis above, and IceRocket sees no real business alternative to adopting it.

I disagree with Jason. I see IceRocket's adoption of reltag as a sign that technorati is succeeding in getting its standards accepted the market place. When a market leader is getting its standards accepted first, everyone else has to play catch up.

[update: I added some names to the inventors list for the reltag microformat per Tantek Çelik's comment]