I just installed Alva and Oskar, the brand new Swedish voice synthesizers in Mac OS X Lion. If you’re interested in a voice synthesizer that doesn’t try to pronounce everything in English, you might want to give one of them (or some other new synthesizer in there) a try. You’ll find the new voices in the Speech preference pane in System Preferences - just hit the System Voice drop down menu, and pick Customize… at the bottom.
I haven’t had the chance to play around with the new synthesizers too much just yet, but my first impression is that they’re surprisingly good at pronouncing words in Swedish. On the other hand, they sound utterly silly when trying to pronounce anything else than Swedish words (more like some drunken Norwegian bastard trying to sound sober).
Give them a spin - voice synthesizers are here to stay.