If you want to use Visual Studio 2015 there is the following hardware requirements:
1.6 GHz or faster processor
1 GB of RAM (1.5 GB if running on a virtual machine)
4 GB of available hard disk space
5400 RPM hard drive
DirectX 9-capable video card running at 1024 x 768 or higher display resolution
It is rumoured to be releasing in October. Obviously it will take some time to roll out the software to all Windows devices and to get carrier and manufacture approval so the vast majority of users will probably receive it well after the October launch date.