The usage of the word Ubuntu in the context of "Ubuntu One" is inconsistent with the Trademark Policy outlined at http://www.ubuntu.com/aboutus/trademarkpolicy
Specifically of note are the following:
"The objective of the Ubuntu trademark policy is to encourage widespread use of the Ubuntu trademarks by the Ubuntu community while controlling that use in order to avoid confusion on the part of Ubuntu users and the general public, to maintain the value of the image and reputation of the trademarks and to protect them from inappropriate or unauthorised use."
The danger of confusion among users and the general public about whether this new service is part of or associated with Ubuntu is extremely high.
"there is no commercial intent behind the use"
The service has clear and stated commercial intent.
"what you are referring to is in fact Ubuntu. If someone is confused into thinking that what isn't Ubuntu is in fact Ubuntu, you are probably doing something wrong"
The service is not Ubuntu and has no association with Ubuntu as a product or community. It merely runs on and works with Ubuntu, on equal footing with other applications like Apache, Firefox, or an Ubuntu user's blog.
"there is no suggestion (through words or appearance) that your project is approved, sponsored, or affiliated with Ubuntu or its related projects unless it actually has been approved by and is accountable to the Ubuntu Community Council"
I am not aware of any such approval or even discussion by the Community Council at this time.
"If you are producing new software which is intended for use with or on Ubuntu, you may use the Trademark in a way which indicates the intent of your product. For example, if you are developing a system management tool for Ubuntu, acceptable project titles would be "System Management for Ubuntu" or "Ubuntu Based Systems Management". We would strongly discourage, and likely would consider to be problematic, a name such as UbuntuMan, Ubuntu Management, ManBuntu, etc. Furthermore, you may not use the Trademarks in a way which implies an endorsement where that doesn't exist, or which attempts to unfairly or confusingly capitalise on the goodwill or brand of the project."
The service clearly falls under the latter list of examples similar to UbuntuMan, and as such is named unacceptably. Furthermore it appears to be attempting to capitalize on the brand, which is similarly explicitly prohibited.
Rename the service to not include the words "UBUNTU, KUBUNTU, EDUBUNTU, and XUBUNTU" nor "any mark ending with the letters UBUNTU or BUNTU", or in an acceptably non-ambiguous manner such as "Cloud Storage Solution for Ubuntu".