I think I found the best way for me to get in compliance. That is
11 characters: [ size=1 ][ b ]
77 characters: Intel C2Q 9450@3ghz | Intel X25-M G2 160GB | MSI Radeon 5870 (on latest WHQL)
80 characters: Ubuntu 12.04LTS + Win7Pro64 | 8GB Mushkin XP2-6400 (4-4-4-12) | Lian Li PC-A05NB
80 characters: Asus P5Q-E (P45 / ICH10R) | Corsair HX650 | Asus U3S6 | Asus VW266H + Dell 2005FPW
87 characters: + Samsung PN50B650 | External Seagate GoFlex 1.5TB USB 3.0 + External LiteOn IHES208 BR
11 characters: [ /size ] [/b ]
To use lines 1 and 6 for formatting. Otherwise it's just far too easy to hit the 90 character limit.
Also, including markup means using colors is basically out of the question. That might need to be revisited. I liked having blue for Intel products and green for AMD products.
I'm not sure the new sig is any less annoying than my old sig though, to be totally honest.
People who don't like sigs are likely better off just.. oh, turning them off in the AT forum options
Cuz this is still going to bug some people. Oh well, I'm in compliance. GLHF, thanks!!