Forgot the anniversary again!
On July 11th, 2004 I switched from Greymatter (after barely a month using it) to WordPress 1.2 “Mingus” which had been released in May of 2004 (had to take a peek in the developer blog on WordPress.org to be sure, but I had a hunch I jumped on the WP wagon1 with version 1.2).
So, I made the switch on July 11, 2004.
The first anniversary I remembered on July 13. I may’ve been using version 1.3 then, with the amazing theme system.
In 2006 I didn’t mention the anniversary at all! I hope that doesn’t mean the era of the Puppy Love had ended.
Now, it’s three years later and switching to something else has never even occurred to me.
1. On the WordPress wagon: Slang Abstaining from other blogging tools. 
I just checked my site tools folder to find 1.2 is definitely in there but I have the sneaking suspicion I may have jumped aboard the bandwagon a release or two before. Greymatter sealed it’s own fate when I found out the hard way that it had a limit on how many entries it could support and my database began to corrupt.
Movable Type came next however, but when they switched to a paid system I chose to move to WordPress, which has been just as successful without resorting to making me pay anything, let alone extra for having more authors.
I didn’t hit any critical threshold with Greymatter but I remember it taking really long time to rebuild. Also, I mainly switched because my hostess’s webspace provider (I didn’t have a personal webspace then) recommended that Greymatter was not used.