Since January 2010 procurement lawyers have known that anyone who  followed the time frame for issuing challenges set out in the UK Public Procurement Regulations of 3 months from the date when the grounds first arose would be wrong as the Courts had declared that to be incorrect.

Under new legislation from the 1 October 2011 the time frame will be 30 days from when you first knew or ought to have known that grounds for starting proceedings had arisen, extendable to a maximum of 3 months at the Court's discretion.  This though only applies where the knowledge arises after 1 October 2011

Whether that will create more certainty is hard to say but it alters the landscape.