Denon announced a new wireless home audio platform today called HEOS. There will be three HEOS speakers to start: the HEOS3 ($300 USD), HEOS5 ($400), HEOS7 ($600).
HEOS works using your existing Wi-Fi network, has both dual-band support, and works with 802.11N networks. There will be a dedicated app for iOS and Android, and the speakers will be able to play content stored on mobile drives, NAS drives, and connected USB drives.
Beyond that, there's no much more information available right now. Denon says HEOS will work with "leading online music services" and "top cloud sources," but will announce supported services at a later time. There will be amplifier and preamplifier products eventually (a la the Sonos Connect and Sonos Connect Amp), but there's no more information beyond that. Even the differences between the announced HEOS speakers aren't clear at the moment.
Without any more specifics, it's hard to judge how HEOS will stack up to its competitors. Denon is planning a press event on June 26, where it's likely the more details will be released and we'll have a better idea how HEOS fits in the rapidly expanding wireless audio market.