I haven't tried this yet, but my contacts tell me this is the case.
The microsoft root certificate has been removed from the final version, and all software that needs to be installed has to be signed with an Orange certificate.
You can kinda understand why this is the case, but it is a nuisance, especially for developers.
I'm hopeful that some way will be found to add new certificates to the SPV, thus allowing me to write software and actually test it on the device!
In the meantime, the Orange co-branded Handango store is the place to get stuff from!