Reports I've seen this morning had more of a negative skew - with greater emphasis on Hammond's significant growth forecast revisions and disappointing stimulus. This plus moderate risk-off tone in markets going into the European open is adding pressure to GBP.
Growth forecast cuts:
2017 from 2% to 1.5% (in line with Bloomberg consensus)
2018 from 1.6% to 1.4% (Bloomberg consensus: 1.4%)
2019 from 1.7% to 1.3% (now sub-Bloomberg consensus: 1.6%).

Other details:
Govt plans capital gains tax on foreign buyers of commercial property, potentially disrupting flow into London office buildings <- GBP negative
Another proposal abolishes stamp duty for 1st-time home buyers up to 300k pounds underwhelmed, with home-builder stocks tumbling

UK data dump in <30mins, including Q3 GDP:
UK GDP just out seems good enough to expect a little relief in GBP weakness today.
Headline meets consensus at 1.5% yoy/0.4% qoq.
Beats in Consumption and Imports (good for domestic demand, albeit less for GBP)
Disappoints on GCFC, which is an area that could have been helped most by Hammond's Autumn Statement yesterday. Domestic component (house builds) were good, but foreign component less (ref: CGT on foreign investment in commercial property).
Closed GBP short post-data. Looking to re-engage again either today or tomorrow.
Bloomberg comment on UK Consumption beat - Best in a year:
Consumers drove the British economy in the third quarter as spending on cars rebounded but Brexit appears to be inflicting a toll on business investment.
Household spending rose 0.6 percent, the fastest pace in a year, the Office for National Statistics said on Thursday. But business investment slowed and net trade acted as a drag on growth. Overall GDP rose an unrevised 0.4 percent, up from 0.3 percent in the previous three months.