There is a newer client available, but they are only sending it out to 'authorized enterprise users' -- they are allowing the enterprises that use their software to download and use the newer version at their discretion. Unfortunately, I doubt whether most companies will start updating their clients anytime soon -- dual boot it is..... unless you download the client from ....errr... shall we say "other" sources. Before people PM me and ask -- no, I can't send them to you.
Also, I've confirmed that the older clients indeed do not work on XP - it's not just XP reporting that they won't work.....