This may be more than what you want to do, but here's my two cent's worth:
I'd love to see the following in a pattern generator:
1) A place to type in your gauge and yarn size.
2) A way to actually chart different patterns with a variety of stitches (and not just images). For example, it would be really cool to generate lace patterns.
3) A database of lace and other types of patterns that you could pick and choose from (and mix and match).
When I first thought of this kind of pattern generator several years ago, I envisioned it for crochet with crochet symbols. Then using your gauge measurements, the generator could create a pattern telling you, for example, how many of a pattern stitch would be needed to fill a space.
I don't see any reason why this wouldn't work for knitting, too. These kinds of generators might be out there already. However, I've not seen them.