No 'perhaps' about it - here's a third "source":
That's how the singular second-person personal pronoun looks in other Germanic[*] languages, too. Heck, even in French, come to think of it -- the Romance languages' roots are somewhat similar to the 'I - me, thou - thee' system, too (right, anyone who took Latin?).
[*]: The further back you go in history you go, the more Germanic and less of a mongrel English used to be.
Christian R. Conrad
Of course, who am I to point fingers? I'm in the "Information Technology" business, prima facia evidence that there's bats in the bell tower. -- [link|http://z.iwethey.org/forums/render/content/show?contentid=27764|Andrew Grygus]