So there has already been quite a bit of fuss over Sandburg. Specifically, the current Deck of the Week Haandy Sandburg. I personally believe that this build is one of the best incarnations of the Sandburg strategy. Which is both praise and warning--I think CodeMarvelous has created a powerful deck, but there is little to no way to improve it beyond this basic "NEXT Foodcoats with a coat of paint".

But this isn't a deck review, this is a card review. What makes Sandburg tick?

Sandburg's flavor text pretty explicitly gives away the name of the game. "Money is power". To use this card effectively, a number of conditions need to be met:

1. Sandburg must be installed and rezzed. This seems like a trivial thing to mention (especially given the 0 rez cost), but it bears repeating--Sandburg is an asset. If he (it?) gets trashed, the card no longer affects the board. Given the potential effect of the card, it seems likely that a runner would gladly pay 4 to trash him, if able. This implies that Sandburg must be protected in a secure server, while you simultaneously try to score out of a second remote.
2. The corp must have at least 10 for Sandburg to be active, and he gets stronger the more money you have. If you only have 9, Sandburg is a blank piece of cardboard. This means that the corp needs to be extremely rich; 10 credits is not enough; you need to have enough credits floating on top that you can conduct your day-to-day business without risking a drop below that threshold.
3. Sandburg strengthens each piece of ice. This means that Sandburg is strongest when he supports many pieces of ice--this is the key difference from the most similar comparison I can find, IT Department, which only strengthens one piece of ice per activation. If your scoring remote is just a Wall of Static, Sandburg is only going to tax a Corroder by a handful of credits each run: but two Walls of Static and a Magnet, and the Sandburg tax is multiplied.
4. The runner should not have alternate methods of paying through a piece of ice. If the runner is willing to let the subroutines fire, Sandburg is worthless. That means that either your subs need to be "End The Run", or something so horrific that the runner cannot afford to let it fire. This basically rules out tracer ice, most bioroid ice, and many of the more interesting code gates and sentries.
5. You have to intend to actually score behind the boosted ice.. Obviously there's no point in Sandburging if you just plan on fast-advancing, shell-gaming, or murdering your opponent.

The combined effect here leads us to a very clear strategy. Sandburg needs a large number of cheap ice, played out of a rich ID, with a straightforward glacier strategy. If you want lots of cheap ETR ice, NEXT ice (Bronze, Silver, Gold) is a good choice--and of course, the in-faction EtF is one of the richest IDs in the game, especially with the sexbot campaigns, boosted by Breaker Bay Grid for extra dosh. And of course, if you're trying glacier, you use Global Food Initiative, and oh hell we've just built a slightly modifed Foodcoats deck haven't we?

So it's a strong addition to an already strong archetype. But it's creating a new panic because it changes a certain fundamental dynamic of Netrunner.

A classic Stimhack article discusses this in more detail, but I'll summarize. In other card games (i.e. Magic the Gathering), when a player is winning, that helps them continue to win. As a result, any card which relies on a dominant board state to be played is unviable, because the help it provides is marginal when you aren't already winning. But in Netrunner, whenever someone commits resources to scoring or stealing an agenda, they have decreased their resources, giving their opponent (who has not committed so many resources) a chance to respond. If a runner goes bankrupt stealing an agenda, they will be off-kilter for a turn or two recovering resources, giving the corp an opportunity to respond (whether that be a kill-combo or just an additional score).

Sandburg changes this. Sandburg is "win more". If you can maintain not just one but TWO secure, well-defended servers, and you can keep 20 or 30 credits on hand, you can create a lockout board state where the runner simply cannot get into any server.

But let's be honest here. If you have enough of a lead that you can keep 30 credits on hand, while also keeping your entire ICE suite rezzed over at least HQ, R&D, the Sandburg remote, and a scoring remote, you have already won.

Still, because it prevents even that last-turn hail-mary run on R&D or HQ, Sandburg frightens runners. Thankfully, the counterplay is pretty strong. You can run Political Operative. Keeping the corp poor is also completely viable--some updated version of Anatomy of Anarchy, Headlock Reina or other siphon-spam looks nice. Cards that break subroutines without looking at strength are options as well: Quetzal, Grappling Hook, and the newly MWL'd D4v1d are potential options, and all benefit enormously from e3 Feedback Implants. Criminal bypass options like Femme Fatale and Inside Job work nicely. On the jankier end, a solid run by any of those Chaos Theory/Hyperdriver/DDoS/False Echo combos would wreck a Sandburg deck.

So in conclusion, Sandburg is a powerful card, and is something you will have to consider when building your runner decks, but he lacks versatility and has strong counterplay options. As a result, I think he'll drift around in the meta for a while, but as players learn his tricks (and cards like Hernando Cortez and Beth Kilrain-Chang are released) he'll eventually disappear.