From what I've heard, Adobe is finally working to upgrade Lightroom to make it more efficient and powerful. This means it will likely be able to utilize the power of your computer better. I'd recommend something with a Quad Core processor, at least 16gb of RAM, decent GPU (Dedicated, not the Intel IRIS graphics) and a decent sized SSD (I have a 250gb SSD in my MBP and it's not enough usually, even though I use externals it's full of shit and LR always takes up a bunch of space on it).