"Cortana and Alexa are still getting to know each other. Soon you'll be able to ask Alexa to buy things, add items to your shopping list, access your Alexa skills, and more," says the brief update on the page.
Yes, "soon" is vague. But it's something...
Typing "Alexa" into the search box in Windows 10 (on the Fall Creators Update version, at least) yields a message saying, "I'll be able to connect you to Alexa soon. Stay tuned!" (This seemingly has been there since February, when the integration began testing with select Amazon customers. But I just noticed it recently.)
Last summer, Amazon and Microsoft announced that their respective personal assistants would be able to talk to one another so customers could opt to use the assistant most suited to a particular task. Amazon and Microsoft officials said last year that they'd make Cortana-Alexa integration available before the end of calendar 2017. Since then, there's been no update on when this might actually arrive.
Given Cortana is set to access Alexa skills via this integration partnership, maybe Cortana's skills shortage is less horrible than meets the eye (?). If we don't hear more at Build, I'd think it must be relatively shortly after.
Soltero also declined to say whether there are any other Cortana-powered speakers in the works. Currently, there's one from Harman-Kardon. I think speakers might not be where Microsoft is focusing; perhaps it's more about conferencing systems, microphones, or other more business-centric peripherals.
I also am very curious how Amazon's announcement of Alexa for Business changes/impacts its deal with Microsoft. When the two rivals announced their integration partnership last summer, Amazon had yet to reveal publicly its Alexa for Business plan. To me, it seems that what Amazon's doing on the work front competes head-on with the way that Microsoft is evolving Cortana.