Let me play devil's advocate here. There may be more types of users out there. But in my mind, there are at least the following distinct types of people that have their own websites:
1. Those that are web savvy but use hosted application solutions for their content (e.g. bloggers using blogspot).
2. Those that are not web savvy, but have paid somebody else to create a completely custom website solution for them (e.g., a charity with a custom database-driven website and CMS).
3. Those that are web savvy and also are technically-adept, so they create and maintain their own custom website solution.
Now, here are some challenges.
When dealing with type 1 folks, they will just use the path of least resistance a.k.a. whatever their hosted application provides. And in fact, it probably is already on their hosted app provider's agenda to include some sort of mobile version to users.
Type 2 users won't even know that you exist and might not even be able to comprehend why they would want and/or need to use your services. The developers that hand-hold them might though. You may want to focus on attracting these sort of developers and catering your service to their needs (e.g., make it easy for a developer to do things she needs to do as opposed to making it easy for a total computer newb to do things he wants to do).
Type 3 users are probably going to roll their own solution and will simply skip over your solution at worst, or at best will use it as an interim solution.
If you can somehow create a kick-ass solution that hosted application providers themselves would want to adopt and roll out for their own users, that would probably yield the greatest reward for your efforts. However, I think the most realistic market right now are the developers who help out Type 2 users. Speaking as somebody who has done this sort of development in the past, here is what I would pay for and would simply pass on to my clients as a cost-of-doing business.
1. I do not have the time, inclination, nor infrastructure to create, maintain, and test against the wide array of mobile devices on the market. But I want to have my cake and eat it too. I don't want to lower the mobile experience down to the lowest common denominator. If iPhone users are used to a specific UI, I want my site to appear and behave like a native app (e.g., maybe using iui.js). Likewise, if RIM users have a particular preference (e.g., some of the older ones had a scroll wheel) I want the mobile version to be optimized for the scroll wheel on the RIM device. Here is what I am willing to do in return: Provide customized structured content, maybe in XML, to your service. You don't have to translate my RSS and distill it down to whatever lowest common denominator mobile version works across all devices. That's not what I want. A lot of my clients have websites with a ton of content and the content itself will have to be adjusted for use on mobile devices, so this isn't entirely a technical problem. I'd much rather provide you with a custom XML document that also has content catering to mobile users and in return you deliver optimized solutions for each platform.
2. My clients are professional organizations. A mobile version of their site needs to be accessible by their own domains. Make it easy for me with instructions on how I can adjust my DNS entries, similar to how Google Apps for Domains works. So maybe if I hit mobile.my-clients-website.com, it hits your servers. I don't care if your servers do the heavy lifting, but I can't be using any other domain for one, and especially not some weird .mobi one that compute newbs can't figure out.
Good luck and hopefully I've provided some useful tidbits for your company to consider (and that I haven't come off as being overly harsh)!