I'm rather confident this will in fact be a great time to be investing in the euro. Whenever assets are manipulated by non-market forces, they always rebound sooner or later. This current bickering doesn't represent anything different from an economic standpoint. Moreover, the next several years will surely bring a few government changes in the EU that should lead to notable economic benefits, beginning with Schröder's ouster in Germany.
This is not a good time to be investing in Turkish lira, however..
Besides high unemployment, low growth, growing socialists policiies, total disagreement between the members, and rejection of their Constitution. I am not sure what non-market forces you are referring to.