David Linthicum had a very good post over on InfoWorld about cloud architects versus enterprise architects. I'm summarizing David but in a nutshell the article is about the need for SOA skills to be a cloud architect. While I totally agree with the need for SOA skills in the cloud space, I think cloud architecture may encompass more than one type of architect.
The uber architect generally just doesn't exist in corporate IT. There generally is a conglomerate of architects that make up the "virtual" uber architect for a corporate IT shop. The cloud really expands on this need because of the different areas of expertise needed in more detail i.e. security, infrastructure and SOA (for sure). Let's also throw in parallel computing for kicks and grins so that we can take advantage of the potential elastic nature of compute nodes. A SOA Architect would have the best chance of having most of the skills in various levels of depth but I think finding all of these in one architect is going to be difficult. SOA itself requires a broad range of skills difficult to find in one person.
Remember the ICC? Integration Competency Center. I'm seeing a future for the CCC or C3 (Cloud Competency Center). In all seriousness it's going to take several architects to screw in the cloud powered light bulb.