Sniper team is by my opinion a sophisticated tactical weapon system, used to support the higher cause, not simply the current situation at hand. As they are highly trained, and it does take more than basic course to actually start to master the trade, they can be used to support infantry actions, or conduct independent missions. Using a sniper team for observation has one huge advantage - availability of precision fire, if the situation demands.
And true, modern sniper teams have evolved a lot, having different weapon systems available (like .338 LM which looks to be pretty good all-around anti-personnel round or fifty cal) when the shot has to be made, skills and means of covert observation/recon have evolved using modern technology. But in the end, the evolving process is first natural, supported by rapidly advancing technology, making new means and possibilities available, or bettering existing ones; and secondly, the role of a sniper team is changing accordingly to the changes in warfare - today's battles in A-stan and WWII's in Stalingrad, for example, are whole world different.
As the talk has gone to modern warfare which tends to be more vague and decentralized/ asymmetrical, the sniper team, as intelligent (not just "smart"), discriminating and precise weapon system is pretty suitable to root out one certain fellow in the market full of civilians, for example, also the only mark left of the team's existence would be the dead fellow and the bullet that hit him/her. And as the existing and probable adversaries will evolve too (stupid ones getting killed, leaving smart ones behind) and learn more that successful guerrilla tactics do include high explosives and precision fire, they will use snipers/sharpshooters too, so there is an increasing need of counter-sniping.
And because of the same reasons, the US military forces, for example, have increased the amount of snipers, and have put more emphasis on DM-s (either Designated Marksmen in squad level or Advanced DMs in platoon level), to increase the unit's range of aimed riflefire, ie having a small-time firesupport available at all times, giving a better chance against those insurgent snipers who have been a total menace in Iraq, for example, and I don't see any reason why current or future conflicts would be any different.
Sniper team is a very valuable addition to combat troops. It does not replace them - snipers can't take over a piece of land, but they surely can deny the enemy to do the same and conduct their plans by their will. Also a very important aspect of sniper warfare is psychological one. Knowing that there are enemy snipers around has huge impact on moral of the troops, especially if the enemy team is successful one. I have witnessed that on trainings here - movements tend to go slower and lower, during one of patrol competitions the inclusion of few sniper teams as counter-force had such a huge impact that half the assignments on the track had to be canceled to ensure that the competition would actually end when it was supposed to (within daylight), or that any team at all would actually make it to the finish line, but IIRC every contestant "died" at least few times.
ADDED: you can always drop a line in PM if you'd like educated opinion from the other side of the Atlantic - I do know quite a few people in that trade, I could forward direct questions.