Well, I'm a Photoshop cultist (so i swear by it). I personally run CS3 but i know it can be very pricey. So a cheaper option is Photoshop elements. That can easily handle all of your batch processing. image size, names, and formats.

Philippe posted an article about picasa, seems a good choice

I use LightRoom, but more for editing than sorting, so, not a valid answer :)

You can use ACDsee, ACDSee allows you to manage Exif or IPTC properties. You can also add legend, keyword, note, autor or value for each images. ACDSee allows you to classify images by category. It is a very good software to manage images. And with the proversion you can manage RAW image. You also use batch function to apply feature un sevral images in same time. For example you can convert or rename several images that you selected. And ACDSee manage a lot formats of image.   

Xavier, the main issue is that with ACDSee this is a process where the user needs to make too many clicks and too often. The batch process is however very useful, but not at all user friendly.  Finally, yes this product does handle many formats including RAW, I am just looking for a good tagging product for JPG files.