Hey guys no need for the squabbling!
I'm with _aravena to a point ... I'm not into shooting professional-grade interviews / documentaries / films, and the internal mic is satisfactory. However, if I did want to shoot a series of videos where I wanted better pickup, I would want something better than the internal mic. Sure, if I had the money I would get the best, most compact solution there is (something like the NTG-2 which looks superb). However, unless I'm doing this on a daily basis I can't justify the cost. As it is I only get out with my camera on weekends, and videos serve more as an aide-memoire of my trips rather than anything more. So in these cases, something between the quality of the internal mic and a $$$ professional shotgun mic would be useful.
And as for the 50 1.8, it's an excellent lens given its cost ... sure it flares a great deal, the focusing is noisy and not particularly accurate, but it's very sharp! ...
I think I will just make do with the internal mic for the moment, at least until I find myself creating many more videos where I need better pickup (although chances are I would need to invest in a better tripod first ... with a fluid head).
Thanks for the suggestions
Any more are most appreciated!
Cheers,
David 
PS. I stumbled across the MKE400 in my earlier research, but many people say the quality isn't very good? And that there's too much hissy treble response ... shame as the form factor looks excellent!