Ho hum. It seems like every three months or so we receive reports that the [insert name of favorite country, state, city, municipality, department or government agency here] pledges to 1) award more contracts to small business and 2) give preference to open source products. The end result is almost invariably the same: Large contracts go to large companies, allegedly because small companies can't prove they can "pull it off", and the usual closed source suspects get all the significant contracts based on some small or insignificant feature of their products that's missing in the competing FOSS product. (Sometimes it's something as blatant as "share point compatibility required", but mostly it's more subtle than that. In a few rare cases the purchaser openly admits that financial incentives beyond the reach of small / open source companies were part of the decision equation.)
Pledges won't change this state of affairs. The only way to break the pattern is to mandate reasonably-sized, neck to neck proof of concept implementations with focus on delivered functionality as part of the bid process. In the few cases I've actually seen that happen small and open comes out on top.