During the last weeks I am working on a new load "model" for these subtitle files. The advantages are that styles will be easier to load/save and the mechanism will be common and more robust. The reason of this rewrite (apart for the support of HTML-like tags in SRT) is to improve support of subtitle displaying in MPlayer.
In the next version of Jubler MPlayer plugin will use ASS instead of SRT subtitle format. Since this is really a major change, any volunteers to check this feature are welcome!