Switching to a bike because of fuel prices is not exactly a common practice as the weather here prevents most from riding all year round and paying extra insurance, maintenance, gear, etc., on a motorcycle is not saving money. Some bikes burn quite a bit of fuel anyhow, in the range of 6-7 litres a hundred which is comparable to a new, economy class car. People will still use a car anyhow when it rains, when they don't feel so well, when it gets cold, when they're shopping. In reality, the amount of days spent on a bike is not that huge and you end up riding it for leisure a lot as well which adds to your gas bill.
With that said, the market is still going away from small bikes, despite the introduction of CBR250.
When it comes to sport bikes there's the CBR125, 250, Ninja 250, 400, GS500. That's it. 5 options.
Yamaha doesn't even bother making one. It's also a shame Kawasaki discontinued the EX500. Should've just updated it a bit and put some better looking fairings and a head light on it. It would still sell well on the strength of its reputation. People are iffy on the Ninja 400 as it's the same bike as the 650, just underpowered, for not that much less money.
North Americans were always thinking bigger equals better. We could use more diversity here. There are some Japanese and European bikes that I would love to see on this continent.