CME 508 does not threaten like Nyxem_e, on February 3rd and every third day of the month thereafter Nyxem.E will destroy users work (see F-Secure's blog) when the worm activates and replaces "the content of user's files with a text string "DATA Error [47 0F 94 93 F4 K5]". Among these files are: DOC, XLS, MDB, MDE, PPT, PPS, ZIP, RAR, PDF, PSD and DMP" "on all available drives", and yes, available = shared drives.

fwiw, I look at published email malware statistics daily, both Nyxem_e and CME 508 are approximately the same in volume reports, and nowhere near sober was last year as far as raw numbers go. But Nyxem.E has legs, it's more like a centipede than a worm, and it's not likely to drop off the radar soon, certainly not before the 3rd of February.

The Handlers diary previously referenced Nyxem.E in More on Blackmal/Grew/Nyxem (file deletion payload.
Source info - see the F-Secure Virus Information Pages : Nyxem.E

The vendors below do not mention the destruction of user work, as of the checking I just did, ymmv.
Also Known As: 

WORM_GREW.{A, B} [Trend Micro],
"It gathers email addresses from files with the following extension names:

DMP
DOC
MDB
MDE
PDF
PPS
PPT
PSD
RAR
XLS
ZIP".

W32.Blackmal.E@mm Symantec

W32/Nyxem-D [Sophos],

W32/MyWife.d@MM  [McAfee],

W32/Grew.A!wm (Fortinet),

W32/Small.KI@mm [Norman],

Win32/Blackmal.F [Computer Associates]

Tearec.A Panda

UPDATE
The CME reference is difficult but not impossible to follow. I'm reading CME links which show "Latest CME Identifiers CME-508", however, that last 508 link has english that says the newest CME-ID is "CME-503  - Date Assigned 2006-01-20". In any event I base my comment that "CME-508" is not a threat because I interpret vendor malware write-ups mentioning CME 503 as the "new" threat called CME-508 at cme.mitre.org. The vendors are listing 503, none are using 508 ......