$100 is a pretty good price for the features this scope has. I'd not worry too much about the software. I strongly suspect they will carry support forward for the older scopes for quite a while yet. You could always give Velleman a call to confirm this one way or the other. Also, the data transfer between the scope and the PC should not be a real issue in this application.
That being said, I do have stand-alone scopes myself, although the long-term recording capability of a scope like this is an interesting feature. It might be worth the $100 for that capability alone. I know things are very different State side, but up here that is less than 3 cases of beer.
On the subject of buying an older scope, like a Tek 465 vs. one of the new 100mHz DSOs (Pick your favorite brand, they all seem very much alike for comparable models. In fact, astonishingly so.) there are reasons to have both. Nothing on the digital side of things under $10K displays a waveform like an analog scope can, and sometimes you just really need that ability. On the other hand, as beautiful a piece of equipment as the Tek 465 is, it cannot record events like a DSO can.
FWIW, I have a Tek 465 and a UNI-T UTD2102CEL. I use both all the time and the total cost for the two was under $525, so it's not an unreasonable idea to have both.
EDIT: Not sure a parallel to USB interface would work for this. There may be bit toggling going on, and that is unlikely to be supported. I tried a USB to parallel interface with my Willem-type programmer recently and it would just not work.