jecasc - 12:26 pm on Jul 6, 2012 (gmt 0)
Actually Opera is a shiny, up to date, standard compliant browser. There is nothing you have to do to "support" it, but to produce regular standard compliant code.
Note also that there are no actual reports on "blogger" having issues when you use Opera despite the warning.
It seems to be plain and simple: "doing evil".