[sokoloff]

I think admission to the summer batch early is compensation enough (and if an applicant doesn't agree, they simply elect to not apply early decision, right?)

Having the plan nailed down that early may allow you to think and develop the idea differently than if you're not sure whether you're doing YC or working a job, what city you'll live in, etc.

Since it's optional for the applicant, I don't see any significant downside that would require an extraordinary amount of additional incentive.