This is a brilliant idea for YC. Having gone thru the YC experience and demo day, I would say that the scarcest resource for YC companies is that bridge between "just launched" and Series-A-fundable or profitable.

A lot of companies can be lean enough to survive this phase on their own, but a lot teams/projects are capital intensive (or slow to get revenue) amd need seed-stage help. There are precious few VCs that focus on this stage (True Ventures, First Round, USV, SoftTech, etc).