MediaStore has the ability to store any binary file type. However, only certain file types can generate the dynamic thumbnail previews
BMP - (Bitmap) Preview and thumbnail
GIF - Preview and thumbnail
JPG - Preview and thumbnail unless CMYK, in which case CMYK icon

PNG - Preview and thumbnail
PSD - Preview and thumbnail
TGA - True Vision Targa bitmap graphics Peview and thumbnail
TIF - Peview and thumbnail

AIFF - (audio interchange file format (Apple)) Audio file icon
AU - Audio file icon
MIDI - Audio file icon
MP3 - Audio file icon
RealAudio - (RealPlayer) Audio file icon
WAV -Audio file icon

ABF - (Adobe Binary Font) Font file icon
TTF - (true type font) Font file icon

ASF - Advanced Streaming format for multimedia - video file icon
AVI - Video File icon
MOV - (Quicktime movie) Video File icon
MPEG - Video file icon
QT - (Quicktime movie) Video File icon

ARJ - (archived file (like WinZip) Compressed File icon
GZIP - Compressed file icon
RAR - Compressed file icon
ZIP - Compressed file icon
EPS - Encapsulated Postscript (Adobe) Image type but no preview / thumbnail
PDF - Adobe Adobe PDF icon 
EXCEL - Microsoft Office Excel Excel icon
WORD - Microsoft Office Word Word icon
Publisher - Microsoft Office Publisher Publisher icon
PowerPoint - Microsoft Office PowerPoint PowerPoint icon
InDesign - Print Design icon 
Quark - Quark icon 
PostScript - PostScript icon 
TXT - Text File icon
Flash (.fla)- 
Flash (.swf)- 

For all other unsupported file types, dynamic thumbnails will be replaced with this icon. Users will still be able to view the asset date for each of these files by choosing to preview.