"...am I reading You correctly in sofar that that You think the browser displays the images based on the info found in the EXIF data..."led me to read even further. I came across this excellent article/series of posts on the subject. If you are new to colour profiles, or want a clear explanation I don't think you'll find a better place to start.
It seems that I was making a glaring assumption concerning colour profiles. I thought that the EXIF tag and the colour profile were inextricably linked. Turns out I was wrong. Each can exist without the other. And it turns out that virtually no applications actually read the tag anyway. I get the idea of the tag - you could use it without embedding the profile and reference a well-known standard profile which your application would already know.
So to my little problem and what I've learnt - I'm still not sure whether Blogger strips out the profile but I'd reckon not. I'm pretty sure EasyThumbnails strips the profile as well as the EXIF when converting from non-JPEG sources. Web pics without a profile will get garbled in some way which is browser dependent: most assume sRGB by default. Safari is currently the only colour aware browser but Firefox 3 is on the way. Embedding sRGB in your web photos is a good idea: it means the conversion has been done and the colours are going to be displayed less screwed-up (but I already knew that going into this little voyage of discovery).
It's about time all photo-image targeted software (including browsers, publishing etc) was properly colour managed then we wouldn't have all this problem.