What kind of extension?   

I thought today was opening day for business returns to be Efiled and Individual returns wont start being accepted until the 29th, so if it was a business extension you should see something by tomorrow (in the next 24 hours) I would guess.

Agree with Lisa, Today is supposed to be opening day for business filing, I have a 990 due today that I previously sent to Intuit, Status has not changed from "Received by Intuit" to "Sent to Taxing Authority" yet, I will keep monitoring, If I get to noon, without the return being forwarded to the IRS I will prepare a paper extension.

An 1120 extension I sent to ProSeries went through today. So, all is well.