Emerging market returns down; shift to frontier markets?

BusinessWeek (using Bloomberg Financial Markets data) has documented some poor returns over the last year for some emerging markets (link to the infographic). Mexico is down 6%, Peru down 42%, Argentina down 17%, Russia down 8%, ... (South Africa is up 2%). Now they're talking about a shift to frontier markets, and list some ETFs that invest in the frontier markets, some of which I've written about before.