NP is hard to use right, even in the few situations where its basically made to shine.
... infestor use has plenty of depth to it without NP (infestors may be less good vs tank supported terrans than others, but theyre still very well worth it when used right - enough to warrant a ghost reply even, but NP hasnt much of a part in this) ... the thought of removing NP it is intriguing, but i dont think thats the way to go, its too late for that, as gifted says. this isnt beta.
same goes for the alternative of super-buffing the ability to become AoE or something, as has been suggested above.. that would probably just brake it and cause general mayhem..
... the best we can hope for is probably a battery of more subtle buffs; some brainstorming on that note:
* increase casting range with 1-1.5 -- would buy some time and make nifty NP use from up cliffs and behind obstacles some much needed extra utility.
*extra armor while chaneling (ideally some kind of one-way spirit-link with the target, but as i cant even be assed to explain what i mean, thats probably hard to get in place in an intuitive enough way)
*Changed duration mechanics, partial suggestions:
incite a delay between interrupted / stopped channelling and the stop of the effect, making for a form of "guaranteed damage" in terms of a few seconds of control
reduction of base duration in favour of extended duration that gradually drains remaining energy -- it always feels like an awkward waste of caster potential to be using NP with full energy infestors but this one is far fetched.
allow infestors to move while channelling but not use any abilities - including burrow - maybe at a slower movespeed (and moving too far away from the parasited target releases it)
... i bet we can do better than this. keep shooting ideas people, and by all means, pick mine apart