I've heard a lot of bad feedback regarding Acer laptops and their failure rate, so Lenovo seems the better option, but it only comes with a 1Y warranty. I'd go with the Dell but the CPU is a lot weaker in comparison to the other laptops.
For any laptop you choose . I recommend you to buy a laptop with preinstalled windows 8 and nvidia gt 610m should be the minimum or if you willing to wait you, buy a laptop that doesn't come with discreete gpu,but with the new intel processor "haswell"beside it will be much lighter than anylaptop you mentioned.
It's more than enough believe me! And i really... really... recommend you to use a laptop with windows 8(very smooth). Windows 8 is fast,fluid,efficient.even with much lower spec than an i5 with windows 8 it looks like a smooth silk laptop.
But future proof i recommend the i5 3210m as a minmum in your need.
The 610m is slightly worse than the hd 4000 so there is really no point buying it unless you need a nvidia gpu for something (though it will be horrendously weak). It might have better driver support for things such as photoshop though. Are there any laptops in your price range with a 7670m?