The Celeron 1020M part is a CPU baked on a 22nm production process, a step smaller than its Sandy Bridge counterpart, which was baked at 32nm. Both the CPU's are dual cores, with the older Sandy Bridge B840 running at 1.9GHz. The smaller die size allows the new Celeron 1020M to run at 2.1GHz whilst maintaining the same 35W TDP. The new 1020M also comes with 1600MHz memory support, rather than a 1333MHz as on the older B840. Both chips have 2MB of cache memory and on die Intel HD Graphics.
While mobile Haswell CPUs can be expected as early as Q2 2013, this will only include the more expensive quadcore CPUs, with lower end dual core CPUs expected during Q3 2013. The Celeron 1020M is expected to stay on the market until Q3 2013, after which Intel will unleash its new Haswell Celeron mobile chips.