Just saw her PBE numbers and such [url=http://www.reignofgaming.net/news/22043-unoffical-pbe-changes-for-10-18-2012-splash]here[/url].
So she isn't super-nukey, but at the same time you can tell how she works and that she will do some good damage. In lane you use human form to whittle people down with your Q, dealing more damage the more hp they currently have, and your W if you need the burst, and your E to either set up kills or stun for an escape.
Once you have your ult, you can then E-Q-W-R-W-ignite-Q to finish them off, using your spider-E when you need to close the gap or escape
She seems pretty fun