There’s a discussion on Whirlpool at the moment that Telstra might be about to increase their data allowance on the $49 cap plan from early December.
Apparently Telstra staff have just got a bump to 1GB on the $39 plan, so it definitely wouldn’t be surprising to see the Big T do this in the runup to Christmas. If you’re thinking about signing a contract with Telstra, you can either wait, or take advantage of their 50% off data offer, which – according to the same Whirlpool thread – expires this month.