Dropping the title: in terms of NXT, no. She isn't doing anything at all with it but she's already over and respected enough for the fans to know whoever faces her is in for quite a fight. It's more important to work on the other girls like Sasha and Charlotte + keep the Emma/Summer feud (great tv) going, so it's okay.
Is she ready: Yes. You can complain about her mic skills and her character all you want, but name a Diva not named AJ Lee with a more defined character than "screaming chick". It sounds like really low standards and something we shouldn't be happy with as meta-fans, but it's the fucking Divas division. Low standards are it's middle name.
Should she get called up: No. Keep signing new wrestlers, keep developing their characters and abilities, and just keep them all on NXT for a while. Milk this Total Divas crap for all it's worth then call up like 6 chicks all at once to replace the old ones nobody care about.
The only one I'd even consider calling up now is Emma.