Considering the 13" MBA

Background
I use machine [1] in my personal and freelance capacity. It's a very good machine, but I would like some extra screen space. Initially the space didn't bother me as I use external monitors. However I don't seem to be occupying my desk that much, so the screen resolution is becoming a burden. I can hear you now: "What about the rMBP?". I bought one of these when they were released, but due to IR issues I returned it. So that's ruled out until it's second iteration, and I have been planning on investing in the new Mac Pros when they're released (I'll need the power when the freelance work above is steadily increased), so it may become irrelevant.

Second thoughts
Perhaps unfairly, I've always ruled out the MBA. But with the updates on Monday, it's got my attention. Things tipping the scale include the massive increase in battery life, the weight, TRIM-enabled SSD (currently disabled on [1]) and it's super-cheap.

Unanswered questions
How significant is the jump from 1280x800 to 1440x900? It seems small from afar, but maybe I'm underestimating it? I do consultancy with lots of development, so use lots of office-related software and various IDEs (eclipse, xcode) and development tools.
What's the SSD in machine [2]?
Any thoughts on machine [2]? I run a lean machine, so the 128GB SSD won't bother me too much.

Ref
1. MacBook Pro, 13", 2012, i7, 256GB Samsung 840.
2. MacBook Air, 13", mid-2013, i7, 8GB, 128GB @ £1149

 

I think you're right, it doesn't sound very significant but I think it'll be totally different when I try it out. I will try and visit the store sometime this week. Only annoyance with the MBA design is the thick bezel. I can see this begin eradicated when it eventually gets Retina - which would be perfect.