In an awesome paper [1] published in 2007, it was shown that irregular English verbs have been dying out (i.e., "regularized") at an incredibly precise and measurable rate. The paper shows "how the rate of regularization depends on the frequency of word usage. The half-life of an irregular verb scales as the square root of its usage frequency: a verb that is 100 times less frequent regularizes 10 times as fast."

[1] "Quantifying the evolutionary dynamics of language" by Erez Lieberman, Jean-Baptiste Michel, [...], and Martin A. Nowak http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2460562/