Dialnorm

Dialnorm is like a briefcase full of bunnies. 

You are having trouble with Dialnorm, aren't you? Yes. You are. You're mixing for TV broadcast and you have questions about these new silly standards. You say "why can't we just make sure our peaks don't go above 0dBfs and be done with it?" Silly girl, you can't do that.

So... dialnorm. The idea is that we want to have all the dialog levels be the same across all kinds of television programs and stations.

Here's a thread about it.

Dialnorm is just the averaged perceived loudness over the course of the program. Dolby later refined their measurement method with the "Dialogue Intelligence" algorithm, but every program, with dialogue or not, has a perceived loudness.
You can use Audioleak to find the A-weighted Leq. This will be your dialnorm.

You want to know what LAeq is, don't you? Heck, Answers.com even has an answer:

LAeq is pressure level measurement parameter. Full form of LAeq is " Equivalent continuous A-weighted sound pressure level". It is widely used around the world as an index for noise.L_Aeq = 10*log[1/(t₂-t₁) * Integration of (P²_A/P²₀) between interval [t₁ t₂]]
where
L_Aeq = equivalent continuous A-weighted sound pressure level [dB]
p₀ = reference pressure level = 20µPa
p_A= A-weighted pressure [Pa]
t₁ = start time for measurement [s]
t₂ = end time for measurement [s]

Read more: http://wiki.answers.com/Q/What_is_a_LAeq#ixzz1HWm0D8BO

None of that is particularly helpful, is it now? No. It isn't. I tend to mix my dialog slammed into hard multi-band limiters peaking at about -12dB FS. The real question is where is the average level in the program? And that isn't something I bother to measure. I'm not saying it's good that I don't measure it. I'm just saying we don't do that here.