Microsoft wants to cull together devices, operating systems, data, and identity to create a pipeline of trust. Microsoft s CardSpace makes it possible for identity to be claimed by digital tokens, so that one can vouch their identity without sharing too much about themselves. If all software had to be properly signed (a level of trust in the identity of the software maker) before it was allowed to be installed on PCs would help eliminate certain classes of malware, and even botnet attacks.
Source: https://threatpost.com/importance-internet-identity-and-anonymity-042209/72566/