Not only that, the handset has also leaked, giving us an idea of what it looks like.
Microsoft's teaser shows three people posing for a selfie, alongside the details of the announcement and the hashtag #morelumia. The event kicks off on Thursday at 10am CET – that's 9am UK time.
But more revealingly, the handset also leaked on Chinese site Baidu Tieba this weekend, alongside a variant called the Lumia 735.
The 730 is said to be a dual-SIM model, while the 735 will have 4G.
The handsets are shown in black and white. Though if past Lumias are anything to go by, we can expect more colours than the rainbow.
Specs-wise, we're looking at a 4.7-inch screen, as well as a 5-megapixel front-facing camera (hence the focus on selfies). We'll have to wait and see whether Microsoft will show off any other new selfie-focussed features. More and more companies are jumping on the selfie bandwagon nowadays, so Microsoft will have to do something pretty special if it wants to stand out.
Microsoft is also expected to lift the lid on the Lumia 830 on Thursday. It's said to be an affordable high-end phone. Microsoft has some impressive budget blowers at the minute, especially the Lumia 530, which costs just £60. So we're excited at the prospect of flagship specs in a cut-price package.
All will be revealed on Thursday, among the madness that is the IFA tech trade show. We'll be there bringing you all the news as it breaks.