This 2010 OECD study [PDF Exec Summary] is a useful source for estimating the relative costs of alternative generation options.
The chart at left (click for full size) shows the levelized cost in USD per MWh from the OECD survey given a discount rate of 5%. The capital intensive energy sources such as nuclear lose their relative advantage if the cost of capital (discount rate) is higher. The next analysis in the report shows the relative costs given a 10% discount rate.
I’ve not purchased the complete report, so I can’t comment on the details of the methodology. In particular, there is a hint in the summary that the projections include a carbon price of US$30/ton CO2. Comments?