If it happens tomorrow, I look to see if I have any available funds lying around in my account to buy more ;-).  Since I get daily dividends, the amount in my account goes up every day.

There's always a chance that you'll lose your money, with any of these investments.  For that reason, it's a good idea not to have all of your money in one place (I currently have a little bit invested in 4 places).  At this point, I could lose a bit of money and still come out ahead, as I've made a 25% return since I started trading last month.

Difficulty is not so high at the moment that dividends are going to shrink like crazy on the next change.  As long as people are still getting paid, most are not going to value their investment that low, that quickly.  While some might, the majority probably won't.  That's not saying that it won't go down a bit, but overall, those that are fearful and bail at a low price will have their shares picked up by people looking for a bargain.  If you panic sell, then you probably will lose money.

For the share price, this is still paying pretty good divs.  While the share price is 10X the cost of AMC, for example, just ONE of its divs is 40 times what their last div paid.  TAT.Asicminer is paying about 10X the VM's daily divs per week, which amounts to 1.4 times the amount that VirtualMiner costs, at 4x the cost (although I do have shares in both of them).  So at this point, it's a pretty good deal.  Later on, it might not be so much.  You do have to pay attention though, because there is the chance to lose a lot more if you don't stay on top of it.