The new EULA for SQL Express 2014 is now out and it states that you are allowed to use this version of the SQL Server for Hosting purposes.
Here is a snapshot of the text.
MICROSOFT SOFTWARE LICENSE TERMS MICROSOFT SQL SERVER 2014 EXPRESS
Page 2 section B
b. Hosting. You may use the software for commercial software hosting services, subject to the following terms:
i. You are Fully Responsible. If you use the software for commercial hosting purposes, you will be legally responsible for all usage of the software by your end users.
ii. Indemnity. You must defend, indemnify and hold Microsoft harmless from any claim arising as a result of (1) your improper installation of the software; (2) any software virus introduced by you; (3) your violation of the terms of this agreement; and (4) unauthorized installation, use, access, copying, reproduction, and/or distribution of any portion of the software by an end user (or any third party providing services to the end user).
iii. No High Risk Use. The software is not fault-tolerant and is not guaranteed to be error free or to operate uninterrupted. You must not grant the right to use the software in any application or situation where the software failure could lead to death or serious bodily injury of any person, or to severe physical or environmental damage (“High Risk Use”). Examples of High Risk Use include, but are not limited to: aircraft or other modes of human mass transportation, nuclear or chemical facilities, life support systems, implantable medical equipment, motor vehicles, or weaponry systems. High Risk Use does not include utilization of software for administrative purposes, to store configuration data, engineering and/or configuration tools, or other non-control applications, the failure of which would not result in death, personal injury, or severe physical or environmental damage. These non-controlling applications may communicate with the applications that perform the control, but must not be directly or indirectly responsible for the control function. You agree to indemnify and hold harmless Microsoft from any third-party claim arising out of end users’ use of the software in connection with any High Risk Use.
iv. Compliance with license requirements. You must (1) inform the individuals who have access to the software that the software is licensed by Microsoft, and (2) bind individuals who have access to the software to terms that protect the software at least as much as the terms of this agreement. You will use commercially reasonable efforts to prevent any unauthorized distribution, copying, use, or pirating of the software.