[tential]

Came here just to see if there would be any support for this device (I'm looking to upgrade from my aging Ouya)

Specs look promising.

Size 4.5" x 4.5" x 0.7" (115 mm x 115 mm x 17.5 mm)
Weight 9.9 oz (281 grams)
SOC Platform Qualcomm Snapdragon 8064
Processor Qualcomm Krait 300, quad-core to 1.7 Ghz
GPU Qualcomm Adreno 320
Storage 8 GB internal
Memory 2 GB LPDDR2 @ 533 MHZ
Wi-Fi Connectivity Dual-band, dual-antenna Wi-Fi (MIMO) for faster streaming and fewer dropped connections than standard Wi-Fi. 802.11a/b/g/n
Bluetooth Bluetooth 4.0 with support for the following profiles: HID, HFP 1.6, SPP
Cloud Storage Free cloud storage for all Amazon content
Ports 5.5 mm DC Jack, Type A HDMI 1.4b output, w/HDCP, Optical Audio (TOSLINK), 10/100 Ethernet, USB 2.0 Type A
Audio Support for Dolby Digital Plus, 5.1 surround sound, 2ch Stereo and HDMI audio pass through up to 7.1
Content Formats Supported Video: H.263, H.264, MPEG4-SP, VC1
Audio AAC, AC-3, E-AC-3, HE-A, PCM, MP3
Photo JPG, PNG
Output Resolution Supported 720p and 1080p up to 60fps

HDMI 1.4b, but no 4K support?

4K support on any Android device would be a joke. The hardware isn't fast enough to run the android interface at 4K. I don't doubt that SOME aspects of 4K could work (Some 4K encodes maybe depending on the capabilities of the Qualcomm chip they used) but to seriously expect real 4K support at this stage of Android life cycle is rediculous.

For Amazon, it's best to not support 4K than to say they do then have users find the 1000 instances that I know 4K won't actually work on the FireTV. It's a $100 device. 4K gaming isn't a possibility, 4K interface would be way too sluggish, and 4K movies would only work in such a small set of circumstances it wouldn't be worth it. So no. No 4K.

Very interested in seeing if this device will run XBMC though. If it does I'll definitely pick one up and my search will be over.

Edit: I think what would have made this box that much better would have been something similar to the Xbox One's HDMI passthrough feature that allows you to plug your cable box into the Fire TV. Imagine watching live TV, using your Amazon controller/remote to navigate, and being able to use voice commands. Switching quickly from Live TV to XBMC on the Fire TV. For XBMC users who use a PVR ya we seen this before, but for average Joe switching from Live TV instantly to the Amazon Prime services would be amazing.