That, and with gas taxes and congestion pricing the buses are damned fast.

For instance, enforcement of bus stops and lanes has the most benefit for Manhattan buses (and to some extent select bus service – although that is a tiny share of total bus service). Outside Manhattan, buses generally do not have dedicated lanes.

In general, most Manhattan bus service is redundant – it duplicates subway routes. There are certain subgroups of riders who depend on bus service (elderly and disabled being a major component) because they have difficulty negotiating subway stations, or can not easily walk a few extra blocks. Crosstown service is an exception, but speeds are slow and distances are relatively short, so improving crosstown service will have limited effect on total ridership.

To dramatically increase bus ridership, such as bringing it up to parity with subway ridership, I think the majority of the effort and resources have to go to the Boroughs.

Realtime info would be great, and could even use text messages or something like twitter, as jass has suggested. (uncertainty is a killer in the decision of whether to use public transit.)
Decreasing boarding time would also be great. A touch card would help, but even better would be a turnstile system that forces people to exit through the rear (this is a pet peeve of mine!)

To really make this happen, though, I think it takes a radical re-design of existing bus routes. There should be a clear definition of goals. For example: Buses should 1) cover areas without subway options, 2) provide connections between different subway lines, 3) provide transit service for those who have difficulty using subways (in that order.)
I believe this would lead to more of a “hub and spokes” system where you have a short routes with more frequent service radiating out from major subway stations, with a de-emphasis on long bus routes, especially where they duplicate subway service.

In these situations, the subway arrival time is also important. That is why that information belongs on the street, at the subway entrances, instead of (or in addition to) on the subway platforms, where the subway commitment has already been made.

The biggest barrier to bus ridership is uncertainty. While some high frequency routes remove that by having subway-like headways, all other lines need a countdown. Put screens in the major stops, and do the rest via cellphone (NextBus in DC uses text messaging)