It is pretty cool to see Microsoft turning up more services on IPv6. If you are a user of Office 365 like my company is then you too can use IPv6 to access O365 resources.
Microsoft has an Office 365 IPv6 Wiki Page that outlines the IPv6 addresses they are using for the service. They are using a lot of /64 subnets but what I find odd is that they have not summarized them to specific prefixes to make filtering (for those that do it) easier. It would also be nice if they published it as an xml or Excel file to allow folks to use wget or PowerShell to remotely get the file for updates and be able to parse it and run a script against it to allow everyone to keep their filters current. I guess the other option is the use dig and a recursive DNS AAAA lookup to get all the same information potentially.
Microsoft also has a portal for getting the URL and IP address information they are using for Office 365 in general and that is here. It is useful because it breaks down by address each of the services so if you are really detailed (perhaps a bit too much?) you can limit based off that too.
There have been some reported outages on the IPv6 side for Office 365 and Mark Minasi and I have traded some jokes back and forth about his experience using his Verizon mifi that provides IPv6 but which often breaks his Office 365 access or at least it appears too - I think we need to troubleshoot it a bit more.
If you are wondering what products from Microsoft are at in terms of IPv6 support then look no further - you can find that information here.