Are these specs pretty future-proof?

Specs:

CPU: Intel Core i7 4510U (3.1ghz, dual-core, 4MB L3 cache)
RAM: 8GB DDR3
HDD: 1TB 5400RPM
OS: Windows 8.1
GPU: NVIDIA GeForce GT 840M, 2GB grahpics memory

Thanks.

EDIT: Also, how long until I should upgrade?

Those specs are pretty decent but, in reality, there's no such thing as future proofing.

Why no ssd? Why not a 7200rpm hdd instead of 5400? You might want to add a 120-256GB ssd as a boot drive and keep the hdd for a data drive.

Make sure that you use a good quality PSU that will power what you have but also allow for expansion should you decide to add more RAM or additional disk storage.

It's hard to say when you should upgrade, future OSes/apps/games may require more resources than current ones but no one knows when that will necessitate an upgrade.

Computer technology is advancing rapidly and systems quickly become obsolete. It has been said that a computer is obsolete the day it leaves the factory. There is a lot of truth in that. Even a high end computer today (which yours is not) will be quite ordinary in a few years.

Your specs are quite reasonable for today. In 2-3 years, who knows?

When you should upgrade depends a great deal on what you do with the computer. The specs of my computer are inferior to yours in every way but it serves my purposes well. I have no immediate plans to upgrade. A serious gamer with your computer specs would be looking to upgrade now.

I would address the speed of the hard drive, as others have already suggested.

All the high tech stuff is future proof until YESTERDAY. Why ?. Because of development stage, by the time one generation is in circulation there's another generation already developed and most of the time get's shelved until previous has payed for it's development and production costs. Any self respecting company would have at least another generation in finishing stage with another one on drawing board. Things are changing at such a fast pace and it still takes time to develop and test newer generations.
techhead, I'm afraid that configuration is barely yesterday proof. Two core processor to start with.

This looks like a laptop. The i7 'U' model is a low power consumption model. The 5400RPM disk was probably chosen because of heat problems. I would immediately replace it with a SSD. Else this system will run a lot slower than it's potential.

There are other things that you should look for. At least one USB3 port and an eSata port would be great.

Is it future proof - NO, the day you buy it, it will be old iron. With a desktop you would be a little safer because it is easy to upgrade. But that's another story.