Gordon Stainforth’s excellent article “The Crux” in the 2007 Alpine Journal (not hard to find on the web) says “The great open-book corner in the centre of Dinas Cromlech that dominates the Llanberis Pass in Snowdonia was named, like the Unconquerables, long before it was climbed - in this case by Menlove Edwards in the 1930s, with a perfect name that reflected the ‘megalithic tomb’ of the crag itself.”
The three ice mega classics in Val Daone we pre-named by the fellow who "discovered" them (Stefano Todesco, if I remember well):
Regina del Lago
Sogno del Grande Scozzese
The story of how this happened is very entertaining (too long to tell here). He went on to climb the Regina del Lago and possibly the Placca, but the Grande Scozzese was climbed some time later by two visiting Austrians.
In reply to Russell Lovett: It seems to usually be the case that a line gets a particularly apt name, it then gains a bit of a reputation under that name and when it finally gets done the FA keeps the original name as that's what everyone already calls it.
'The Groove' at cratcliffe springs to mind. Similarly i guess 'Wizard Ridge' and 'smiling wall' will both keep their names when they eventually get done.