its already planned in the roadmap.
I normally do not eclipse, so are not too found of it either, however, I would like to see that they made the eclipse plugin stable first...
it is nicer to have one really stable GPD (even if it is in eclipse), rather than two shaky ones...
Afaik, it wil always be eclipse based. The standalone version will just use one 'perspective' that is customized so it doesn't look like it is in eclipse and you are not able to switch. The thing is that a default eclipse has so much in it (CVS, XML editor etc...) that it would be realy stupid to ditch that. Even BPM 'vendors' are switching form their prioprietary designers to ecplise based ones.
Why jboss doesn't supply a standalone GPD for designing the workflows, instead of the plugin for eclipse?
I think it is better for the peoples that doesn't use Eclipse.
IMHO JBoss provides GPD as Eclipse plugin because it targets developers (as far as I know jBPM GPD is a part of JBoss IDE now).
if you need end user solution you can try RUNA WFE (Workflow Environment For JBoss jBPM)