So are you saying that it is now the case that any configuration of MB soft core is free in Webpack whether Vivado or ISE / Spartan 3/6? Does that include all relevant SDK tools and peripheral IPs reasonably needed at this point?
It's free for any 7 series (and US/US+) FPGAs and SoCs, SDK and 170+ IPs are free as well, and there are a lot of useful IPs in that list. You can even build multi-core/triple modular redundancy systems (free IPs for that are included). Most of these IPs connect through AXI/AXIS bus, so building a system in many cases (if you only use these pre-packaged IPs) is really just a mouse job with no HDL code involved. MB softcore can be configured to have all features required to run Linux, and there is a Linux build designed specifically for the core.
Lattice actually comes out the "hobbyist friendly soft core" winner here (at least in the past) due to Mico32 being freely available. Pity that dealing with Lattice (and to some extent X/AI) is so hobbyist unfriendly in general, Altera probably being the best of the bunch as for web site / licensing hurdles et. al.
For hobbyists like me who make their own boards, Xilinx wins hands down due to free IPs like DDR2/3/3L/4 memory controller, aforementioned Microblaze-related infrastructure, 10/100 MBit Ethernet MAC, FFT core, DDS waveform generator, memory-mapped PCI Express core, all AXI/AXIS infrastructure cores, and many others.
And if you want to make your own, just implement an AXI/AXIS interface, and this will allow you to connect your module to just about anything. There is also free AXI Verification IP that makes writing testbenches much easier as it provides an abstraction layer so that you can write your code in terms of AXI transactions, and not individual signals. It's written in SystemVerilog with the full source code available, as well as very comprehensive demo project and detailed documentation explaining how to use the core.
No other vendor comes even close to all of that. Which is a shame, as competition is always good thing for end users.