Nuclear weapons used within this decade? I doubt it. They are such destructive weapons that even one bomb could devastate an entire region from the fall out. If I had to pick a country to use it this decade it would be Israel. Say if Iran is practically on the verge of acquiring nukes, Israel might just think to it self, right sod this not taking any chances and launch tactical nuclear strikes (assuming they have them) and if not then possibly strategic ones.
Now onto the future I think there is a very real chance nukes could be used. Say NATO and Russia. NATO won't budge on the Missile Defense Shield so Russia said it will develop more offensive capabilities (which is far cheaper) to counter it. We are talking Cold War levels of mutual distrust here. Anyone who's read their Cold War history will know there have been a few occasions (not just the Cuban Missile Crisis) where NATO and the WP came dangerously close to WWIII. One only has to look at the sparks that triggered previous global conflicts. It really doesn't take much and as long as nukes are around, the possibility they will be used will exist.
Other conflicts where nukes could be used-
China vs Taiwan and US.
China may decide to launch a nuclear tipped 'carrier killer' DF-21 ASBM against a US carrier fleet to wipe it out in international waters. Reason is because the US should have a robust anti ballistic missile shield soon and the way to increase chances of a hit is by going nuclear. Being in international waters it is unlikely the US will retaliate against the Chinese mainland.
India vs Pakistan
As we can all see from the news Pakistan is under severe attack from Islamic militancy. India may at one point come under a sustained terrorist attack emanating from Pakistan in one form or another. India seeing the anarchy in Pakistan decides to launch a major land, air and sea assault to destroy Kashmir/Islamic militants. From a position of great weakness Pakistan retaliates with nukes and India fires nukes back.
Iran vs Saudi Arabia
Say Iran does acquire nukes, the Saudi's will probably follow suit and the US will probably turn a blind eye to it like they did with Israel and Pakistan. Most of the Middle East oil reserves just happen to be sitting underneath the population of Shia Muslims. The Shia's are repressed by their Sunni rulers in Bahrain, Saudi etc and Shia Iran want's 'liberate' them and extended it's influence. It would start by creating 'Hezbollah's in those regions and things could quickly spiral out of control. Say the GCC send in troops to quell an uprising, Irans's well armed and trained proxies fight back while Iran decides to intervene, say starting with a clash of the navies in the Persian Gulf which would then get each others airforce involved and finally ballistic missiles and perhaps even nukes.
I recommend the following WWIII fictions:-
Total War 2006
The Third World War
Arc Light
Defcon One