"It's not enough for ICS+"
I own a Blade running 4.2, and RAM certainly isn't a limitation. Processing power is.
My understanding of how Android will handle it is simply that apps will be killed off earlier when not in active use. On my Blade I seriously don't see this as being *too* early. As an ex-T-Mobile Pulse owner, with its 192MB of RAM, I know what not having enough RAM is like (try having music playing, then replying to a text and it kills your music).
Keeping apps open for longer would be nice, but so would quad core, a better camera, more resolution etc. It's a budget phone, we're not going to get a Nexus 4.
"Most phones now are 1GB+"
Another argument I see is that most phones these days are 1GB+. But they're also becoming quad core: again, this is a budget handset, you can't have it all.
The only two points where my Blade are crippled are looking up friends on Latitude and the task switcher taking a while to load. Both of these could easily be down to its meagre 600MHz CPU.
So instead of comparing with other phones, or the minimum requirements for Jelly Bean, or whatever other meaningless numbers we might see, what are the real-world, substantiated (ie not based on speculation) reasons why 512MB of RAM is a problem.
Edit: I asked the question on Reddit and got a really helpful answer
Edited by KenBW2, 15 April 2013 - 11:32 PM.