The respective world champions at 10,000 and 5,000 metres have been in outstanding form this season, with Gebrselassie regaining the world 10,000m record in Oslo last month and Komen becoming the first man to run two sub-four minute miles back to back.
As far as the Kenyan Komen was concerned, there was a particular point to prove following his exclusion from the one-to-one challenge over two miles on 31 May between Gebrselassie and the world mile record holder, Noureddine Morceli. Last month Komen managed what his rivals failed to do in breaking eight minutes for the event, although for him there was no $1.5m (pounds 950,000) bonus.
Komen defeated Gebrselassie over 5,000m last season, but the Ethiopian was still recovering from winning the Olympic 10,000m title on an Atlanta track so hard it left him with blisters. This time both come from a major championship.
Like the two 5,000m contenders, Wilson Kipketer won his event in Athens without seeking a world record; thus Seb Coe's 16-year-old 800m mark of 1min 41.73sec, which the naturalised Dane equalled last month, still stands.
When Kipketer came so close to setting a new record in Stockholm, Coe commented that he would probably have broken it had he chosen to run at Oslo a few days earlier. The Oslo track has witnessed a series of middle distance world records, but Zurich - another of Coe's favourite hunting grounds - has also had its share.
Iwan Thomas has pulled out of the 400m because of his continuing knee problem, but Roger Black runs against a field which includes the man who beat him to Olympic gold last year, Michael Johnson.
The 100m brings together the main players in the World Championship final, while two British sprinters from the next generation have an unusual opportunity.
Dwain Chambers, who lowered the world junior record to 10.06 last month, and Christian Malcolm, silver medallist behind him, will run in a farewell event for Carl Lewis. The 36-year-old former world and Olympic champion, who retires at the end of this season, faces a field composed entirely of junior athletes. One generation salutes another, and all that.
Jonathan Edwards, so dissatisfied with his silver medal in Athens, has the chance to put some of the bad memories behind him in what will be only his second competition in six weeks. Steve Backley also has an early chance of revenge against the unheralded South African who beat him to the javelin gold, Marius Corbett.