forget about win7 ... it is incompatible with almost everything
....
as for the linux .. I use linux in every day life, on job, for job .. it is my primary OS .. I had to make one windoze box for the elco stuff ... in general you "can" use linux but it is pain in the ....
if your uC of choice is PIC
the mplab 7.1 works under wine 1.0, I think 8.x works too but I never tried.
piklab (native linux app) have support for pickit 2 both with firmware 1.x and 2.x as long as for many other programmers. you have pic asm as native linux and piklab will help you install all the compilers under wine ...
so you can use boostbasic, boostc, boostc++, c18, ccs c, c30, picc lite, jal ... and programm directly from linux if you have pickit2 or compatible device ...
you have geda/gspice/pcbdesigner/eagle for the hw design .. it is not as nice a some windoze tools but it is free.
that's about it ..
I heard AVR is much better support but I never tried..
If you want TI MSP430, it works perfectly under linux (eclipse + mspgcc)
I personally found doing elco dev on linux to be pain so I moved that to windoze ..