The thing is, there are plenty of states that don't get polled enough, while a safe Republican state like Kentucky has been polled 10 times. States that have been polled fewer times:
Colorado- An undeniable swing state.
Nevada- Again, an undeniable swing state.
New Mexico- Ditto.
North Dakota, Montana, Alaska, South Dakota, etc.- Some polls have shown Obama stronger than normal in these states, but we've had so few polls, that it's impossible to tell.
South Carolina- Only one poll here, showing McCain only up by 3. I'm not saying poll South Carolina every week, but some follow up here would be nice.
Indiana- Polls showed this competitive in April, but since then we haven't gotten anything.
New Hampshire- Again, undeniably a swing state.
Maybe the polling companies are testing the key Senate race where Mitch McConnell might lose in a Dem year and are waiting to start polling general election presidential matchups until closer to the time?
Personally, I agree that it would be preferable to see more swing-state votes, but financial incentives might be a cause here.