Short and sweet: Sucks.
Long and boring, supports "basic" video, audio and photo content including Divx/Xvid (720x576 max resolution), MPEG2 (VOB etc.) and some other useless formats. MP3, WMA etc. without DRM (no complaints there) and JPG, PNG etc. on the image side.
Interface is the bare minimum, you have the standard "Videos", "Music" and "Photos" sections as well as USB for external devices you may connect to it, you cannot search for ANYTHING and all are listed in alphabetical order. If this was 1998 and this was a 40GB Hard Disk I would say "Brilliant" but a TB worth of flicks, tunes and pics and it's simply a mess... Advice is come up with a good filing structure and stick to it.
Format support for video is pretty terrible, yeah it plays Divx and Xvid, but that is just soooo 90s! How about some h/x264 support? And even container support, no MKV? AVI really? I am not expecting HD format support on a $100 device but no support for h264 means that I have to re-encode all of my Handbrake DVD rips to Xvid as opposed to just copying them from my media center and that is crap.
Ok well I could almost forgive the support limitations if I could change the damn aspect ratio! See the problem is that the thing expects all video to be formatted in 4:3 (or 1:33 or something close to it) with zero support for anything else. Considering the thing supports 720p/1080i upscale over HDMI I can't be the only person in the world who expects their 16:9 content to not stretch vertically! Total Shite.
Last point is support. Toshiba has yet to release a single firmware update or answer the paltry 2-3 comments on the support site regarding this product (forget searching the web for support, as no one is stupid enough to have purchased this product... well almost).