(Source.)"Many of you are wondering what's up with the patch and the ladder reset. While I've sprinkled some information around, it's about time it was all mashed up in one easy-to-read location.
The Story -
Once upon a time our internal legacy development teams wanted to put some much needed love into Diablo II. Diablo II doesn't have tournaments with millions of dollars swirling about them, so it generally took a back seat to the patch development time of our other legacy titles. But one day the planets aligned, and it was finally time to give the old girl a new coat of paint and break a bottle of champagne over her bow with the release of a patch. This went well. Meetings were held, the community was involved and polled, and an extremely long list of ideas and changes was created. That list was then cut down to changes felt to be either necessary changes, or easily implemented to ensure development time was efficient. This also went well.
Not long after, the alarm bells sounded. The patch was progressing quickly, and the release was potentially imminent. Early on it was decided, and somewhat of a no-brainer, that a ladder reset with coincide with the patch release. With the patch progressing well, a potential release of two weeks was estimated, and as always this is the exact amount of forewarning given to players and the community before a ladder reset. An announcement was made quickly and immediately to ensure a full two week notice was given. There are many reasons for this standard two-week notice, not the least of which is that most players don't understand the meaning of ladder and non-ladder, and how a reset affects their characters. Following any reset our support departments are flooded with issues related to the change of their characters, so we attempt to inform beforehand and avoid any unnecessary confusion.
This was all well and good, the community was excited, and the developers were having fun and enjoying being able to work on Diablo II again. Then, as it tends to do, reality struck. (http://forums.battle.net/thread.html?topicId=16888549346&sid=3000) Work had to be swiftly and immediately realigned and has and continues to be focused on addressing issues for a different title to resolve a very serious issue.
The Now -
The Warcraft III patch is now on the Public Test Realm (PTR) and testing is progressing. Once that patch is released work can shift back to Diablo II and the 1.13 patch, and we'll be working to getting that patch up on its own PTR as soon as possible. This could be a matter of weeks. Once it's up and in a testing state for all of you, it's then going to be a matter of ensuring the features are good and it's a solid patch. The more people we have testing the patch and providing valid feedback, the better the patch will be, and hopefully the quicker it will be released. So that's my challenge to you. You've been waiting a long time, you want an awesome patch, you want a reset. To get all that, we need good solid testing and feedback, reproduction steps for bugs, detailed descriptions of issues or errors, etc. So once this goes live on the PTR, I expect some crazed-youruinedtheeconomy-testing."
As previously predicted here, the other higher priority issue that was prolonging work on the patch was, indeed, the Warcraft III patch, which is now entering its final testing stage. As noted, Bashiok has said that we will most likely be seeing Diablo II's patch in a PTR (Public Testing Realm) in as little as a few weeks- a short amount of time in light of how long we have been waiting. Whether this can be trusted like his previous post about the patch being released as early as the end of April is yet to be proven.
On a similar note, suspicion continues to rise among fans as a previously-held stickied thread by Bashiok on the official Diablo II forum on the Battle.net board here was unstickied- one that was clearly labeled by Bashiok as the official patch information thread. Whether this will doll out to become a fact of significance only time will tell.
Credit goes to Lethal_Weapon and Variance for the tip-offs- be sure to give the two some rep points if you get the chance. Also, necronergal has another thread for this in the Diablo II forum here.