Recs.
Updated
SpecsUpdate
Pros
Pro Runs Linux well
Most reports of linux on the T440s have been positive apart from some issues with the trackpad by default which can be solved by installing libinput:
https://wiki.archlinux.org/index.php/Libinput
Pro Good Keyboard
If you're programming, you're going to spending a lot of time using your keyboard. You want something that is comfortable and allows you to type with the utmost speed.
Cons
Con Heavy
Thinkpads are not known for their lightness. They are built tough and that means they will weigh a bit more than most laptops.
Con Some issues with the trackpad with Linux by default
Being a one piece touchpad, Linux has had some driver issues with it including unwanted clicks and random cursor movement/scrolling.
Issues with palm-detection in Linux can be fixed by installing libinput:
Con Boring design compared to other Ultrabooks
ThinkPads are not known for fancy designs.
Recommendations
Comments
Out of Date Pros + Cons
Con Computers may have man-in-the-middle adware installed
Lenovo is shipping computers preinstalled with man-in-the-middle adware called Superfish. It's a web proxy that can hijack any web session, including encrypted/https sessions. And since the root certificate is the same for everyone with private key present on the machine that's now publicly known, anyone can spoof any site to people using Lenovo laptops. Currently, it affects IE and Chrome browsers with Chrome expected to push an update that will block the certificate soon.
Uninstalling Superfish won't remove the certificate.
Lenovo are standing by their choice to install adware.