I really hope the new Airport Express will be a Powerline-product!
Powerline is nowadays more reliable and faster than wireless networks, and other companies are already making Powerline devices with Wifi.
The Airport Express will be exactly that, but the advantages of an audio-output and USB-port would be new for a Powerline device which makes it also really interesting for non-Apple users too (pulling new customers towards Apple).
And why would Powerline be implemented in the Airport Express you say?
1. Extend a wireless network by using the Powerline signal (current AE's need Gigabit-input (not often available) or to replicate the existing wifi-signal, which is often weak because you are extending it with a reason, and therefore providing slow internet. With a signal from the grid using Powerline, which is provided from a second AE at your router, you have a hassle-free, fast, reliable connection which reaches further than your existing wireless network could offer.
2. Router in the basement or at another wifi-unfriendly location in your house? Using Powerline you can place the AE wherever you want internet.
3. Don't like wireless signals? Interference? Frequencies too crowded? Too slow? Powerline is the solution while you do it the Apple-way including it's advantages.
4. No ethernet-connection for your Apple TV at your TV, while you need the network for streaming and the wireless signal is too weak or too unreliable (for you HD-videos)? Powerline!
5. Future Apple products which implement Powerline??? iMac, Mac Pro, Apple TV, Macbooks,...? Saves you the cable clutter and hassle, which is exactly the Apple-way of thinking.
As you can see: Powerline can profit from Wifi (et vica versa) and Powerline can profit from the Gigabit connection (et vica versa). Add the existing USB-port for printers (and external drives??) and the audio-output and it's a wonderful device which introduces something really new since it's debut.
