If you're on anything higher than 3.0, then you've already lost the ability to use a pure software hack. So in your case you might as well update now.
EDIT
Actually, forget what I said. Apparently there's still a chance of a software hack in the future at 4.1.0. Don't know how long that could be though.
There's no "chance" of it happening. It's confirmed softhacks will come for 4.1.0 eventually, but Kate and Co. are waiting for the chip revision before release since it isn't patched yet. There's been no mention if the hack can apply to 5.x+ or not though, which I assume it could if it hasn't been patched yet.