Apart from one odd medium format lens (Fuji 100mm AE), I've never encountered a lens that metered. If you wanted to ask whether the body will still meter with the lenses: No adapter will transfer any kind of information between body and lens. But in this state a camera can still meter and do aperture priority AE at working aperture - provided that that is not disabled. The latter is no issue of any M4/3 body I tried so far, but it is a fairly widespread restriction on budget DSLRs, so we might see cameras that don't meter with adapted manual lenses once M4/3 grows an entry level.
Almost all adapters will fit every Nikon lens, from non-AI to G - but I've seen complaints about some unidentified no-name adapters that won't fit pre AI lenses unless you file down a (useless) ridge, probably a issue of the workshop owners owning no non-AI lens to test against.
G lenses have no aperture ring any more, and are stuck at their smallest aperture (which is much less useful than being stuck wide open!) unless you buy an adapter that provides a ring to manipulate the (internal) aperture lever.