From this, in First's timetable booklet...
First 13 is being cut back from Monday 27th October, so that it will no longer serve Central Station. Merry Oak and Harefield will therefore lose their direct link to Central Station, but can still use the 13 to catch the train from Woolston, or change at Woolston to the three, which still runs through to Central Station. Details here and new timetable here.
...to this, courtesy of Traveline.
From the same day, Stagecoach is revamping its routes in Romsey. The 32 and 33 will disappear and be replaced with an enhanced 66 running all the way to Winchester every half hour Mon-Sat daytimes. The Cupernham parts of the 32 and 33 routes will be covered by alternate journeys on the new 66. The new timetable is buried on Stagecoach's website, but can be found on Traveline. The 36 is not affected.
The 66's new route in Romsey, according to Traveline. So that's clear, then. It's a bit easier to understand on Stagecoach's website.
As many commenters on this blog have already remarked, Xelabus have a new website and it is a huge improvement on what they had before. It is now far simpler and easier to use and features route maps.
Don't forget that Gardbus 139, until now a Sunday-only service, now also runs on Saturdays.