Seen a few versions of this floating around didn't really like the simplicity of the spammer so I added: Album Year, Track # & Sample Rate. Bitrate is also included though I just used that addition from another script that was floating around on last.fm forums

Spammer Example:
@ShaneO playing on Clementine :: 311:: Track #10 :: You Wouldn't Believe :: Greatest Hits '93 - '03 :: 2004 :: 1020kbps :: 44100KHz

__module_name__ = "xchat-clementine"
__module_version__ = "3.0"
__module_description__ = "Get NP information from Clementine"

# Added Album Year, Track # & Sample Rate

from dbus import Bus, DBusException
import xchat
bus = Bus(Bus.TYPE_SESSION)

def get_clem():
    try:
        return bus.get_object('org.mpris.clementine', '/Player')
    except DBusException:
        print "\x02Either Clementine is not running or you have something wrong with your D-Bus setup."
        return None

def command_np(word, word_eol, userdata):
    clem = get_clem()
    clemp =  bus.get_object('org.mpris.clementine', '/Player')
    clemmd = clemp.GetMetadata()
    metadata = clemp.GetMetadata()
    if clem:
        pos = clem.PositionGet()
        bitrate = unicode(clemmd['audio-bitrate']).encode('utf-8')  + "kbps"
        bitrate = ''

        xchat.command("me playing on Clementine" + " :: " + unicode(metadata['artist']).encode('utf-8') + "::" + " Track #" + unicode(metadata['tracknumber']).encode('utf-8') + " :: " + unicode(metadata['title']).encode('utf-8') + " " + ":: " + unicode(metadata['album']).encode('utf-8') + " :: " + unicode(metadata['year']).encode('utf-8') + " :: " + unicode(metadata['audio-bitrate']).encode('utf-8') + bitrate  + "kbps" " :: " + unicode(metadata['audio-samplerate']).encode('utf-8') + "KHz")

xchat.hook_command("np",    command_np,                 help="Displays current playing song.")
print "xchat-clementine 3.0 plugin loaded"