I try to write a syntax plugin, which should be rendered to div, and I've found that it's impossible to do it correctly at least in 2009-12-25 Lemming.
I've tried to use 'stack' PType for my plugin as described here:
http://www.dokuwiki.org/devel:syntax_plugins
"stack — Open paragraphs will be closed before plugin output, the plugin output wraps other paragraphs"
Ok, but paragraphs doesn't close before my block, so code
Some text
<testblock>
Some text
</testblock>
Some text
is rendered to
<p>Some text
<div>
<p>
Some text
</p>
</div>
Some text
</p>
Here is a quite simple test plugin in attachement. Please, fix this problem before new release, because without stack PType it's impossible to write usefull block plugin.