combining files should make a big difference, as I said, at the moment there are 149 http requests.
I know it shouldn't be benchmarked against the likes of wordpress because they are completely different but at the end of the day most of our clients don't understand that and you can't expect them to. Really it is about user experience, if that is a bad one well then something is majorly wrong.
I have clients on ADSL2+ saying it is taking over a minute to load the cms. These clients are easily pulling a mb a second. The 1mb download is nothing, most connections can handle that in seconds, it is how it is delivered.
For example, we could Mod Tiny MCE to load all the image from one gif sheet rather than 36 requests those images make on loading the cms. Even better, remove Tiny MCE form the load as it isn't needed until you want to edit content.