I agree with dave3. I started out slow in July 2011, learned from my mistakes and with a lot of help from people on this board. When I stopped mining my relatively small 10 GPU farm this past April I had earned ~550 bitcoin, which I havn't sold. Now my expectations for the one SC Single I have on order are much more tempered. Probably won't do any better than my GPU results over a similar timeframe and most of that will be front loaded.
I totally agree that one's expectations about the age of ASIC mining should be tempered. But from the way that people are piling in with orders, it seems that many are pretty much frothing at the mouth about it. I'm not sure about this, but it may be that we have already invested more in undelivered BFL hardware than we currently have invested in the equipment currently running the network.