Lance;
Having been on both sides of the fence, I know that it is hard for router development engineers, especially at legacy vendors, to know what is really going on in the market. But for ISPs operators, the audience of this group, your question comes across as a "duh" moment.
Everyone I know is using GBICs on 95% of new purchases. We are a regional provider in a relatively rural rural region (Maine and New Hampshire). Even in this rural market 95% our purchases next year will be GBICs running GE. However, most of those GBICs will have some involvement with Wave Division Multiplexing to get multi-GE rates. 10GE is just not needed right now by us, but I suspect people in more populated regions are using it.
POS, Sonet and ATM are dead except for small players and some legacy providers. I am sure this is still significant niche.
The only reason someone isn't going to use a GBIC on a new GE purchase is because the vendor is requiring that we use SFPs or another pluggable standard to get what we are trying to accomplish. Cisco's 3750 is a good example of a formerly GBIC purchase that is now a 4xSFP purchase. I can't think of any reason why you'd install equipment (new or used) today that uplinks at less than n x GE unless you have a large legacy investment or user base. If you question was a GBIC vs 1000BaseT question, that is a slightly different animal. Where ~100% of our networking purchases probably contained a GBIC somewhere last year, probably 5-10% of those this year are mostly 1000BaseT where copper is usable instead of fiber. This makes server -> network connectivity easier and less expensive. Hope this helps, Deepak Jain AiNET