Ok, so... Maybe I'm a little late for this, with all the new tags and such, WM_COPYDATA commands are a little left over...
But anyway, I just f*cking learned how to send WM_COPYDATA commands to Audiosurf with VB so I made YAAP!
Screenshot:

Features:
· Can be launched anyway, launch AS first or YAAP, it's your choice!
· Can be minimized to tray to leave AS playing without interference
· All the WM_COPYDATA commands were included
· What every other Audiosurf player has

Minimum requeriments:
· Windows XP
· .NET Framework 2.0
Recommended requeriments:
· Windows Vista (just because you don't need the .NET Framework then)
Changelog:
1.0
Initial release!
1.1
Added lines to the playlist to organize it more
Added function to open a saved playlist
1.2
Corrected "Lines instead of blocks" button text
Fixed a bug that made YAAP impossible to minimize to tray
Fixed a bug that made Audiosurf impossible to restore the normal window state when Always on top or AOT, no border was used
1.3
Remade the whole interface
Added function to save your playlist with your own name, leave the textbox blank and it will save it with the default name ("playlist")
Updated the ID3Lib.dll
To do:
Open playlists created with Winamp, foobar2000, etc.
Make the playlist moddable 'in-program' (you can modify the playlist by editing the .txt file)
Add a function to stop to see scores between songs
Special thanks to e_- without the code of
his player I would've never learned how to send commands
