Okay, done a bit of research, and here's what I've found:
As a result, when the $350 (U.S.) gadget debuts early next year (Apple recently delayed the launch from December), the HomePod won’t be able to do many of the things the Echo can. Amazon offers thousands of “skills” (voice-activated apps) that let users do a range of things (including buy stuff from Amazon). The Google Home, which debuted earlier this year, is similarly endowed.
The HomePod will be mostly limited to playing tunes from Apple Music, controlling Apple-optimized smart home appliances and sending messages through an iPhone.
Looks like my friends were right: it's basically going to be a music playing device with none of the impressive capabilities of the Google Home or the Amazon Echo. It will have the capacity to send messages through a synced iPhone, but it won't be able to answer your questions like Alexa or Google.