With the new CMMI version 1.2 getting CMMI level 4 and level 5 is not a cake walk. The expectations from the SEI(producer) is high. The lead appraisers are screened for High Maturity appraisals. Considered to last year numbers like >40 companies getting level 5 and >30 getting level 4, this year it's only 9 level 5 and five companies got level 4. All the previous appraisals(level 4,5) conducted in last 1 year is audited by SEI again. This is a welcome sign for real quality lovers. However more insight on SPC should be provided by SEI.