Most applicants will be approved instantly. There are some circumstances, such as the specifics of your business model, that may require a brief manual review. At most this will take 1 business day, but many reviews will be much quicker.
The good thing about doing this upfront is that you don't have to worry about running into any issues (like unexpected shutdowns) as your processing ramps up.
The idea behind this offer is to help launch more startups. If you are a pre-revenue start-up or just started to collect fees for your product, then shoot us an email at accounts@braintreepayments.com, and we're happy to help.