Also, I am potentially doing this through my current employer rather than as a skilled independent migrant.
Edit: I'm from London
OTOH the independent visa gets you much better terms than the sponsored one. The sponsored one contains a provision stating you must leave the country if you're unemployed for a month (IIRC). BUT you will need to prove more experience than you currently have to get the independent PR visa. If you have the BSc it knocks a few years off the experience requirements.
I found the australian immigration website and a web community called PomsInOz very helpful for these things.
You would have issues getting a different visa than the 457 though, they require 5 years experience if you do PR by yourself.
Does the 457 visa mean that there is no requirement to meet the educational requirements for a Software Engineer on the SOL?
Effectively, my lack of BSc won't stop me if I can get on a 457?
The 457 requires you "have skills, qualifications, experience and an employment background which match those required for the position". I never finished uni and got a 457 in 2008 (I'm Swedish). I did have ~10 years of experience though.
The Department of Immigration have lots of information on their site, http://www.immi.gov.au/.
I'm trying to figure out if they will accept me being sponsored by my employer with my 2.5 - 3 years experience and DipHE... basically, will they take me despite my lack of BSc?