Update (3:35pm Eastern): Issue seems to be resolved now, according to BlackBerry.
BlackBerry World seems to be down for several users across the globe right now. When opening the app, user are presented with a "BlackBerry World is currently undergoing maintenance." pop-up. We've reached out to BlackBerry for comment, and are still awaiting a response.
Apparently, this issue has been ongoing since 2:30pm Eastern, so we're hoping it can quickly get resolved within the next couple of hours.
Is BlackBerry World working for you? Let us know in the comments!