So, which EVIL (like the acronym, btw!) only have a thumbnail sized sensor?
Pretty much every EVIL camera I've seen as a MFT camera or Sony NEX. The former use a 4:3 sensor that's only 11% smaller (IIRC) than an APS-C. The Sony uses the aforementioned APS-C sensor (but ruins things with a Big Ears & Noddy UI). Now, unless you're a giant, I'd hardly call this thumbnail sized.
There are some oddities out there such as the Ricoh GXR. But this has an interchangeable lens and sensor, so the latter can vary according to the lens.
Personally, If I was on a budget, I'd need some real convincing not to look beyond the Lumix G2 and GF1 cameras.