<<The new regs do not unconditionally require clinical trials for FDA approval of biosimilars/biogenerics; rather, they give the FDA the authority to determine on a case by case basis whether clinical trials are warranted—see #msg-48581353.>>
In the interests of precision, what you link to is the law our Congress enacted. Regulations are something various government agencies such as the FDA and IRS promulgate to interpret the law -- the FDA website lists the regulations they have adopted. http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm
Such regulations could certainly give guidenace on when the FDA will waiver a requirement for clinical trials.