in terms of guitaring and flutes, I'd say you might like Alkonost (but Viter being the far more obscure band, you probably already know them).
Viter cover Skyforger on their upcoming split EP; Skyforger are quite similar to fellow Balts whose newest album was one of the best of 2010, Metsatöll
[ame=http://www.youtube.com/watch?v=WOBkRLNlUx0]Metsatöll - Minu Kodu[/ame]
and you should probably check out Kamaedzitca's 2008 album, Weeping Twilight's 2009 album, and Chur's 2009 album. All great Slavic stuff with clean vocals. Goverla's 2010 album might also be worth a look if you like Negura Bunget and Marțolea.
oh, and I'm not a huge fan of this band, but the song vaguely reminds me of Krov Tikae
[ame=http://www.youtube.com/watch?v=Myunwp9jUCA]Athlos - Talos Unleashed[/ame]
as does this (similarly epic/melodic, but more raw in style)
[ame=http://www.youtube.com/watch?v=YK_6QiYrh8k]Zpoan Vtenz - voi kalnai kalneliai[/ame]