@arifsali @thesacredpath: look at this example (in Norwegian, but you will get the picture: http://hageblogger.blogspot.com/. At the the right sidebar, there are several blogs showing, some with thumbnails, some without. It seems like bloggers from, for instance the blogspot.com platform, will get thumbnails showing automatically, but bloggers from WordPress and other platforms don't.
(Sorry that my latest post showing in this roll is a text message in it self - (really a *bad* example in this case, but all my posts have always been showed as text only in rolls).
@raincoaster: I usually have a initial image for my posts, and I wish for this to be reflected at blogrolls as a thumbnail (enclosed with the automated text feed by the RSS). Of course I don't expect anyone to make an image to represent my blog, I would not ask for anyone to do that much work. What I am looking for, is the automatic process that seems to differentiate between the different blogging platforms.