Thanks for all the thoughts, all. As far as our website processing goes, we don't do any direct sales, it's all through our ecommerce partners, so it's a matter of what they support. Doing something like Paypal, or, from what I've seen, ClickAndPlay (I never saw it until today, but checked it out a bit), that's legally more direct sales, which creates a lot of legal challenges that we don't currently have to deal with.
The service that we use for our ecommerce platform is FastSpring. If you would like to send them a note asking for ClickAndPlay support, I'm sure that would mean a lot more coming from potential customers rather than from me. There's a simple contact form here, if you like:
http://sites.fastspring.com/arcengames/order/contactAs MrPopov mentions, GamersGate does already have the preorders set up for LotS, as they tend to have all our various beta stuff early, but so far Steam has always waited until the first official release before carrying our titles.
Hope that helps!