From US Airways via email.

“Over the last year, we’ve been investing in the products and services you want most. Now, we’re excited to introduce new technology enhancements to deliver your Preferred upgrades.

Behind the scenes

To increase your chances to upgrade, our system checks for upgrades frequently throughout the day and keeps you notified right up until 24 hours before your flight.

In your inbox

We’ll email your upgrade status to you, clearly showing your seats by flight. If you didn’t get an upgrade, we’ll tell you why. Throughout the day, we’ll keep checking and email you if a First Class seat becomes available.

Your favorite seat

Prefer a window? Love the aisle? We’ll do our best to match your seat to the preference you set in your profile.”

The biggest improvement in my opinion is that their system now checks for upgrades frequently throughout the day. Although I wish their systems would check for possible upgrades beyond 24 hours prior to departure. While I’ve never experienced it, I believe it was entirely possible for a lower status member to “trick the system” if you happened to call in at the right time and obtain an upgrade even if there was a higher status member in the upgrade queue. It’s nice to see US Airways making positive improvements to its systems that benefit elite members. US Airways is growing on me, and living as close as I do to Washington National (DCA), having a little US Airways elite status is a positive thing.