I've got my name down for a Taser course. I can't do it until I'm confirmed in rank though. Seems like there us a few more courses opening up here too though, which is good. They've relaxed some of the rules of who can carry too, previously it was response officers only, now NPT can carry.
So, back in 2011 ACPO decided that taser could not be carried by probationers or specials. The reasons were poor at best.
A few months back the NPCC have revisited this decision and referred it to the CoP for guidance, so I think the chances of specials and probationers being able to carry are pretty good. There is certainly a reasonable amount of support from the NPCC.