The event invite doesn’t really tell us much except that it will be about “More than One”, which we can only allude is a reference to the HTC One M9 Plus. Also based on the handset pictured in the invite, it seems that the dual camera feature could be part of the HTC One M9 Plus. The dual camera setup isn’t new to HTC as they used it in last year’s HTC One M8, so it looks like they could be bringing that feature back to the One M9 Plus.
Aside from that not much else is known about the handset for now. So far we have only heard rumors about the handset’s specs. This includes a slightly larger 5.2-inch display compared to the One M9, a QHD resolution which is also an upgrade from the One M9, and it is also said to be powered by a MediaTek SoC under its hood. There are talks about 3GB of RAM, 32GB of storage, but take it with a grain of salt for now and hopefully on the 8th of April all will be revealed.