From the moment iiNet announced its NBN pricing, this was pretty much inevitable; Internode's cut its NBN pricing.
Not that the official release mentions iiNet in any way shape or form; the official word is that
NBNCo has made significant revisions to its Concentrating Virtual Circuit (CVC) pricing model that address major cost overheads previously present during the ramp-up period of the NBN commercial rollout. These changes, along with other changes in underlying supply economics since July, have enabled Internode to offer its customers a range of great new retail plans to launch the commercial phase of the NBN.
At the entry level, $10 per month has been cut from prices, and the mandatory voice bundling is also gone from all plans. Internode's offering four data tiers to iiNet's three — you get the choice of 30GB, 300GB, 600GB or 1TB — across speed tiers labelled as Bronze (12/1Mbps), Silver (25/5Mbps), Gold (50/20Mbps) and Platinum (100/40Mbps).
Given that actual retail plans for NBN launch sites go live tomorrow, this is fairly carefully planned release timing. [Internode]