certificate now for the most part is e-certificate. you'll get it 3-5 business days after oath. For passport, unless traveling urgently, apply for a regular one. i got mine in under 2 weeks.Still waiting for email and oath instructions.
Hope the other guys who are done with the entire process share their experience/processes undertaken after they took the oath - eg. how to request for certificate and then how to apply for passport? processing times?