This probably won't affect many people but just in case....
I did my annual renewal for my visa earlier today in CM. Last year - my first renewal on a marriage visa - we used my wife's income to meet the 40,000/month requirement. This has now been disallowed. Foreign husbands now need to show 40,000/month themselves or have 400,000 in the bank (in the husband's name) for at least two months before the extension. This isn't a change in the law - the head of CM immigration has decided to implement this himself (why, I don't know but this is what the officer said). I was allowed to renew the visa based on my wife's income, having done this last year, but was told next year, this wouldn't be possible. You also need to supply a photo of you and your wife together (and a photocopy of this), a new requirement which has just been introduced in the last couple of days.