I'm not sure exactly what you are looking to do with your new laptop, but I can tell you my story.
I needed to get laptops for my two children, whom I homeschool, ages 7 and 8. Originally I was hoping to keep everything in the house Apple, but just could not justify spending $1K+ on each of my kids computers. At this age, a lot of the school work they do is flash based (which automatically eliminated the iPad from being a contender for us), so I wanted something that was inexpensive but had decent graphics performance (so I was looking for an ATI graphics options versus the Intel integrated graphics).
I ended up picking up two of these Dells:
http://www.bestbuy.com/site/Dell+-+...lack/2560082.p?id=1218335741659&skuId=2560082
After spending $1500+ on my MBP and some upgrades, I have to say I was VERY impressed by these new Dells at the sub $300 price point. They seem to be a lot better quality than the early 2000s Dell Inspirons I had a long time ago. With Win7, the performance is very good as well.
I see now that they offer a Core i3 with HDMI output that exactly match the specs you are looking for.
http://www.bestbuy.com/site/Dell+-+...lack/3504588.p?id=1218407014253&skuId=3504588
I'm not sure what the battery life on that model is, but on ours we are getting around 5 hours depending on usage.
If you don't mind throwing in some extra cash after purchasing the laptop, I would put in extra memory and try putting in a faster hard drive (I have a Seagate Momentus XT hybrid drive which boots really fast on my MBP). Upgrades are much easier in the Dells due to the removable panels (as opposed to removing all those screws on the MBP).
I would think you would be really happy with the performance for such a cheap PC.
I have nothing against Windows, I used it forever professionally as both a software and systems engineer, but really needed a change and happily adopted the Mac full time (I had used Macs for many years but never as my sole OS). If Apple made lower cost laptops aimed at younger kids, I would have probably went in that direction.
We are, however, very happy with the price/performance and reliability these new Dells offer.
Hope that helps a little.