Sorry, this would better go to twitter - but I'm not twittering.
Another thought. And not because I want to bash ExtJS, but because I've been interested into the GPL, open source licensing and the implications for over a decade.
IANAL. The best situation for the company behind ExtJS would be if extension developers stay with the LGPL for their extension (or switch to a more liberal Apache license). The people who buy the OEM license from Ext can then use the extension. If someone releases his ExtJS extension as GPL, to be more "in line" with ExtJS, people with the OEM license cannot use the plugin, because it's GPL (they can use the extension in a way that their customer need to download and install the extension on his own, but this is most often too cumbersome for customers. They are not allowed to distribute their commercial application with the extension or any code which references the extension).
The plugin writers do not gain anything for staying with the LGPL license, but Ext LLC gains a lot. It makes their OEM license much more valuable. If every Plugin writer switches to the GPL version, this could have an impact on the OEM sale. Especially because most enterprise won't touch GPL software.
The best for a plugin author is to also go to a dual GPL/commercial license.
Very interesting situation.
Update: Very interesting