"We have received your tax return and it is being processed. Unless there is a processing delay or you owe other taxes, you should receive your refund by February 1, 2011"
That is a general, and generic status update. It is telling you that your return was accepted and is going through the IRS System now. IRS uses a system called CADE to process tax returns. While it was originally intended to be able to process returns within 24 hours allowing for direct deposit in 72 hours, various last minute tax laws passed each year since 2008 have prevented the IRS from fully using this system.
Back to your status message, if the IRS finds nothing wrong with the return (you own federal taxes from a prior year, non tax off-sets, ect) they will release the funds on 1/28. The IRS gives a two business day grace period since since banks will not make the funds available on 1/28. This is why it says 2/1. The IRS could also experience delays that they had in years prior. The Where My Refund online system is also not updated daily. According to the IRS it is updated weekly, and many have said it is something on the weekend. I would check back sometime tomorrow.
If approved your status will change once more later this week.