Ha! Don't count on it dude, with the types of people leaving (i.e. low usage users) it's only going to free up a small amount of bandwidth, plus there will be a steady increase in "leech" type users due to tightening of copyright laws.
Xnet will be seen as a haven for downloaders (like you) so the likely outcome is even less bandwidth to go around. Think about it....
FWIW, I don't download much - just linux ISO's (no, for real!) and updates for my O/S - although using Arch linux, the updates come thick and fast. One advantage of free open-source software is the absence of desire or need to use pirate software - I recommend it! I guess I go through some data watching streaming video from news sites, the daily show, youtube and tomshardware. And national radio and radiosport.
I download less than 10GB most months, which is why I like the pay-per-GB policy of Xnet. I'm also sticking with Xnet (for now) because - youtube and other video streams aside - the speeds are acceptable. Comon' Xnet - let's get the international streaming stuff sorted, OK? Oh, and I use naked DSL and VFx - no cursed Telecom for me!
Don't forget to take into account the fact the Xnet legally has to dob you in if it suspects you may be downloading copyright material ("no we would never snoop our users traffic, even if their usage was detrimental to the network"), ROFLMAO!!!!, dude if there was ever an easier way to get rid of "problem" customers.
I wasn't forgetting this. It's this intrusive policy which means I'm surprised there are so many P2P and torrenters still on Xnet. I suppose encrypting clients and private networks and torrent sites are easy enough to use though *not that I'd know how. Ahem*
Xnet (and every other ISP) will be looking for ways to cut costs (due to increased infrastructure costs), the only ISPs that are likely to be able to afford decent amounts of bandwidth (and also make a profit from it) are the companies that own international connections - i.e Telecom / Telstra. Unless the government steps in... good luck if National get in (which they will)...
In business only the strong / good survive. If you continue to offer a service which users are willing to pay whatever dollar for, and you make a dime, you stay in business even when times are tough. If your service craps out, then no matter how cheap it is, no customers will be happy or stay, and therefore you lose. I really hope Xnet won't fall into this trap. So far, personally, so good - but if these threads are to be any guide, then they may have fallen into the classic (NZ ISP) trap of reaching beyond their grasp.