While perusing through my XM trademark search I stumbled upon this filing by XM for "XM4Home". Judging by the date, this has been in the works for sometime now, but as usual, the listing provides little details of what this thing actually does. Anyway, here's the info:

Registered Trademark (Link)

Word Mark XM4HOME
Goods and Services IC 009. US 021 023 026 036 038. G & S: digital audio radio receivers, antennas and components
Standard Characters Claimed
Mark Drawing Code (4) STANDARD CHARACTER MARK
Design Search Code
Serial Number 78691500
Filing Date August 12, 2005
Current Filing Basis 1B
Original Filing Basis 1B
Owner (APPLICANT) XM Satellite Radio Inc. CORPORATION DELAWARE 1500 Eckington Place NE Washington D.C. 20002
Attorney of Record Cynthia Greer
Prior Registrations 2547677;2902875;3016015;AND OTHERS
Type of Mark TRADEMARK
Register PRINCIPAL
Live/Dead Indicator LIVE

So sparking my curiosity, I dig back into a Bear Stearns report outlining the analysts tour of XM R&D facility in Florida from earlier this month and find this nugget on upcoming XM devices:

Next generation home-based receivers likely would also support wireless networks and solutions that are becoming increasingly popular.

So the XM4HOME receiver could be a wirelessly connected device that streams satellite radio content to other devices, possible through 108.11b/g WiFi. But then the "solutions that are becoming increasingly popular" still leaves room for more speculation.

Turning to Bank of America's report of the same XM analyst tour, we may find a bit more clues:

Other new services/products include weather, voice controls, and ability to transmit data to devices (ie podcast, audio books).

Now, we know about weather and voice controls. So what about the ability to transmit data like podcasts and audio books? Note in the trademark filing that it says "digital audio radio receivers" and not "satellite radio receivers" as normally listed.

I could speculate like crazy about what the final functionality of this device is, but I'll leave that up to you guys. If the XM2go is any indication, XM4Home would be a more "revolutionary" concept in how satellite radio is looked at as a home entertainment category.

(Note: That's the Polk XRT-1 pictured above just to give a visual reinforcement.)