^First non-English accent? Sylvester McCoy might have something to say about that.
Tennant's Accent is English? Sure sounds quite a bit like Scottish to my "less than trained ear"? Not as thick like Amy or McCoy, but, to me it definitely sounds quite similar to Scottish.
??? He was talking about Capaldi, as far as I understood. Though we don't actually know yet what accent he'll used.
Tennant's own accent is Scottish but he adopted a what's sometimes called an 'Estuary English' or 'Mockney' (mock cockney) accent for DW.
Anyway, even if one were to regard Tennant's as a Non-English accent, McCoy was still first.