I seriously doubt that we'll ever be able to reach a state where 100% of search results are genuine or where 100% of the desired files actually show up. With experience, after a couple of weeks of intensive use I assume that 99% of users learn to recognize fake files (there are other ways not mentioned about, such as file sizes, unable to search host etc). I have used LimeWire for 3 years and have downloaded maybe a handful of fake files in my life, that would be 0,001% of all downloaded files. I would rather have the production team focus on ways to find GENUINE files rather than filtering out the unwanted ones.

An interesting take on the fake file is what several music companies have started doing recently, they flood the network with low quality files or files where 1 in every 5 seconds of the song is blank. It makes it harder to find genuine files but still I've only taken the bait 3 times in 3 years.

Just my 5 cents.