Features already included are:

Player:

Seeking in files

Volume/Balance

Shuffle play

Repeat play

Equalizer

Playlist editor

Visualization:

Spectrum Analyzer

Oscilloscope

User Interface:

One line mode al'a WinShade in WinAmp

Timer Elapsed/Timer Remaining

Double Size option

Full Winamp 2.0 skin support

Gnome/Afterstep/WindowMaker dock app

GTK Interface for requesters (with theme support)

Auto remove borders if the WM has support for it

Plugins:

Visualization

Effects

Input

Output

Misc:

Streaming/Shoutcast(1.0/1.1)/Icecast support

Fast jump in playlist

Scroll wheel support

Save to wav option

Saves http streams to HD

HTTP authentication

Plays mpeg layer 1/2/3 also wav and formats supported by mikmod

Proxy authentication support

Compiles on other systems (FreeBSD, Solaris, LinuxPPC, AIX, Irix)