Will the new 2015 "MacBook" be able to run VMs effectively? Windows especially
As far as I know, the new MacBooks as of today have only begun shipping from online orders, so I won't be able to speak from personal experience - but I would be very wary about the MacBook being able to handle intensive tasks like Parallels, especially in tandem with Visual Studio or Eclipse. 

Parallels' recommended hardware specs for running Windows 7 include "...an Intel Core 2 Duo, Core i3, Core i5, Core i7, or Xeon processor (Core Solo and Core Duo processors are no longer supported)." The new MacBook has sufficient RAM (8 GB minimum) to fulfill their requirements, but the Core M processor (see the tech specs) will be the issue with running these types of tasks on the MacBook. 

Check out the benchmark details here compared to the i7 that you are using currently and you'll see a noticeable difference - Core M running at 1.1GHz which effectively makes it a mobile processor if anything.