If you are talking about the standard voltage, dual-core, Celeron market there will be a few new 45nm CPUs to come in Q3 2009. Traditionally Intel is working hard to introduce new notebook platforms and parts in back to school period and at the same time it prepares itself for the big Xmas shopping fest.
The new CPUs that will replace existing 65nm Merom based Celeron T1700 and T1600 are called T3000 and T3100. These names do sound much better and they will hide 45nm Penryn based CPUs under the hood. The T3000 will work at 1.8GHz has FSB 800, 1MB of cache and TDP of 35W, while T3100 shares the same specs but it works at 1.9GHz.
The predecessors, T1700 work at 1.83GHz has FSB 667, 1Mb of cache and 35W TDP while T1600 shares to specs and works at 1.66GHz. The T1700 sells for $86 while T1600 is priced at $80 and you can expect similar pricing from the new T3100 and T3000.
They should be ready for Q3 2009 launch.