Just trying this out.

Plague Lord
-Plague Censer
-Twisted Crown of the Horned Rat
-Liber Bubonicus
244 points

Plague Priest
-Plague Censer
86 points

Festering Chantor
-Eye of the Horned Rat
-Dispell Scroll
110 points

Festering Chantor
-Dispell Scroll
-Dispell Scroll
110 points

----------550 Character Points

20 Clanrats x2
-Spears
-Musician
-Standard Bearer
270 points

20 Stormvermin
-Gatling Gun
-Banner of Burning Hatred
245 points

4 Ratswarms
-Upgrade
260 points

-----------775 Core Points

20 Plague Monks x3
-Additional Hand Weapon
480 points

10 Plague Censer Bearers x2
340 points

-----------820 Special and Rare Points


Strategy: The Clanrats and Stormvermin stay together and run along the right side, follwed closely behind by a Festering Chantor. The left is taken by 2 units of Plague Monks, the Plague Priest, and the other Chantor. The middle is rushed with the Swarms in front, followed by the Plague Lord, then the last Plague Monk group and the Censer Bearers on the flanks.

Good, bad, anything?

I'd slightly increase the size of your units, maybe merge some units together into one larger (especially so for the clanrats, IMHO 20 is a bit small). In a skaven army I field 25+ units as a rule(24+ if I put a character in it), and this works for me. Apart from this I like the army a lot. Plague monks are great, and as is the Plague Lord(I wouldn't give him a censer though...).

cheers,
BrotherPaul