When Games Workshop decided they wanted a new way to screw over their customers, they switched from pewter to Finecast models. Finecast is a type of plastic resin that is supposed to offer "finer casting" than the pewter models do, but the real reason that they switched is because the price of pewter has gone up as the price of most metals has gone up lately, while the price of plastic resin has gone down. Thus, each Finecast model costs them only a fraction of what casting a metal one would.
However, GW, being the money-loving trolls they are, they decided not to pass on these savings to the consumer and actually increased the prices, despite the switch in production actually costing very little, as they simply used the same die that they used for the metal models for the Finecast ones. This means that the profit per model for Games Workshop has gone up, on average, about 300-500%. This pleases Games Workshop.
However, there are other problems associated with Finecast. The most notorious problem is that this first batch of Finecast has apparently come out with lots of bubbles that destroy detail or ruin the model entirely. Bubbles are well known to resin modellers as a result of rushed or poorly-handled molding, and the first Finecast batch resemble someone's first attempt at home-casting. While drunk.
As if to make a bad situation worse, Flash, the little plastic line that runs along the surface of a model and is a leftover from the Casting process, is notably harder to trim on Finecast miniatures because the new material is so much softer. The traditional way of cleaning flash away is easy - simply scraping it away gently with a hobby knife's edge. Doing this with Finecast Models, of course, tends to leave them with unsightly scratches. In a surely unrelated note, GW has released a new kit for trimming Flash from Finecast Models - it goes for about $20 (PROTIP: Keep your money, and instead use a small toothbrush - that disposable Colgate Wisp thing is fuck-awesome for Finecast work because it's small and has a hook on the handle that can be used to carve out any gunk you can't gently brush off, or just throw some money at Tamiya or some other company prone to making shit that actually works).
And if that weren't bad enough, the second wave of Finecast is doused with chemicals that keeps the resin from sticking to the mold. Fine in theory (reduces mold lines) but it also keeps your paint from sticking to your model.
Luckily, the minis are packed in clear plastic boxes, leading to legions of fans to poke and prod the boxes in order to avoid getting poorly cast models. This in turn pissed off the staff, for obvious reasons.
Luckily, GW has a returns policy, and they don't tend to check, which has lead to less than honest fags reporting multiple faults and getting multiple 'free' models.
Finally many customizers are up in arms over the fact that you can no longer get at some of the cool metal parts that the old metal models had, because Finecast attaches some of the parts for you. Now you have to saw the model apart if you still want those unique and shiny pieces.
In any case, Finecast has caused quite a bit of rage among Warhammer players and modelers on /tg/.
Musical accompaniment for when you assemble your Finecast miniatures provided by Don Ho.
There's a rumor out there, saying that in a couple of years or two (or even less maybe), Finecrap will be replaced by plastic. Take it as you want. If you are ok with Finecast, then "Meh, ok." is the answer.
Update: Not even likely. According to my local store the Finecast process has now been updated to produce cleaner and better quality models. This, apparently, (wait for it) is due to the fact that there's a "computer chip" involved in the process now, which "knows exactly what to do" to get consistent results every single time. So it seems the above notion that it was previously a drunken home-brew job was probably correct.
To be fair, their new Finecast range certainly IS better. I've had a few models from their "new" process and they've been perfect first time, versus previously having to return each model two or three times for replacements because they were so shit. Unfortunately, GW have now put the prices up on everything from this range, so that 3 measly Oblits or a single Juggernaut Lord will now cost you £35 and £30 respectively, which is a joke. They're also started packaging their Finecast stuff in boxes rather than blister-packs so you really CAN'T see what's inside them until you fully open your purchase.
Not that this is an obstacle in any first world country where you can open boxes in stores before buying. Where the fuck do you live where you can do that without being thrown out the store? <Try asking at your local gaming store. Or just leave the store after purchase, go around the corner and open it there if you really must, no fucking law against that, even though it completely negates the point of checking before you buy.
I can't see them moving to plastic if they've just invested in a new system to produce Resin models.
Just for all your information, finecast is dead.
 Shitcast in action
A Finecast Assault Marine backpack. Jesus, look at this.
A Chainsword, looking all in the world like a rabbit chewed on it.
Games-Workshop charged full-price for this. Think about that for a second.
This is what Finecast and GW's rote incompetence has brought us. A nipple-gina!
Quality Control? What's that?