The east coast never remembers that people actually live in Perth. Airlines schedules, sports fixtures, concert tours, etc. To live in Perth is to suffer in paradise.
As for the actual discussion about ports in Europe; given that Qantas already serves three locations direct from Perth I can't really see it going backwards from there. I know that the tiff with Perth Airport really put the brakes on for a while, but there appears to be progress there. And once everything is consolidated to T1 I think we'll see a steady increase improvements in services available. It might not be all Qantas/all Europe, but adding the Qantas domestic network as the on-flow for international arrivals gives incoming airlines some good flexibility. And there's the bonus of not having to transit a 3rd country for travelers that want to go to England, France, Italy. While nominally you don't need to actually go into [Insert_Country_Here], there may be the risk-averse "Well if either flight gets delayed for some reason I may need to stay - which includes going through immigration in the transit country". This might not describe you, but I know people who think this way.
And when traveling to east-coast Canada from Perth I try to avoid transiting in the US if I can. The US is a special case, I know, but the point is that I can understand the sentiment.
I have no doubt that as aircraft fuel efficiency continues to climb other carriers will also see an attraction of having a direct-to-Aus route via Perth without having to buy ultra-specialised aircraft to fulfill the requirement.
AJ was on record in the past for QF9/10 that the vast majority of pax are originating/terminating in Perth anyway, so it has been viable sans-Melbourne for a long time. PER-FCO clearly does its job. Time will tell for PER-CDG, especially after the Olympics. I don't see Project Sunrise displacing any of these in the short term. SYD-LHR direct and the SYD-SIN-LHR route will just offer more options to get to Sydney. And if enough people have the same "I'll never fly to Perth under pain of death" attitude as some posters here then those people were never going to use the existing routes anyway. For those types of flyers Project Sunrise isn't competing with the Perth routes. It's competing with any of the one-stop-in-Asia-or-ME routes.