What sort of climate zones would be present if Earth was tilted like Uranus?
A paper on this topic just appeared: Multiple Climate States of Habitable Exoplanets: The Role of Obliquity and Irradiance.

In case of 90° obliquity, summer and winter would appear together with day and night, respectively. This means, in summer one hemisphere completely faces the Sun with 24h daylight a day causing extreme hot summers. The temperatures in winter very much depend on the hemisphere. In the Southern Hemisphere, oceans are predominant compared to the continents, having a very low albedo makes it possible to store the heat in summer. Thus, the winters in the Southern Hemisphere are still warm. In contrary, the Northern Hemisphere becomes rather cold in winter due to the small heat storage in the oceans.

The equator region is the coldest region on the planet, since this region has the lowest incoming solar radiation (Fig. 1a,b). This could lead to sea ice building around the equator region and provides an alternative hypothesis to Snowball Earth (Williams, 2008): The High Obliquity, Low-latitude Ice, STrong seasonality (HOLIST) hypothesis for pre-Ediacaran glaciation.

The warm poles and the cold equator significantly change the dominating jets. The mechanism can be explained by the thermal wind equation:
$$
p \dfrac{\partial u_g}{\partial p} = \dfrac{R}{f} \dfrac{\partial T}{\partial y} ~~,
$$
where $p$ is the pressure, $u_g$ the geostrophic zonal wind, $R$ the specific gas constant for air, $f$ the Coriolis parameter, $T$ the temperature, and $y$ the meridional distance in meters. The thermal wind equation shows that the vertical change in zonal wind is proportional to the meridional temperature gradient. Thus, the sign change of the meridional temperature gradient causes a sign change of the zonal wind. This means that the dominating jets turn into easterlies due to the reverse meridional temperature gradient (Fig. 1c,d).

However, the climate also depends on the initial condition of the planet, i.e., multiple climate states are possible for the same parameters. In case of 90° obliquity either a so-called "Uncapped Cryoplanet" or an "Aquaplanet" state exists (for further details see Kilic et al., 2017). An Uncapped Cryoplanet has large areas of sea-ice around the equator and a permanent open ocean at the higher latitudes. This climate type posses a previously unknown meridional atmospheric circulation which is neither a thermally direct nor indirect cell but rather a superposition of both cell types (Fig. 1e).


Figure 1: Uncapped Cryoplanet (left column) and the Aquaplanet (right column) for a planet with 90° obliquity in southern summer: (a), (b) zonal mean air temperature, (c), (d) mass stream function (colour, positive for clockwise overturning) and zonal-mean zonal wind (contour, positive for westerlies), and (e), (f) the poleward energy flux for the eddy and the mean contribution, the total energy flux, and the meridional heat flux in the ocean. Note: The figure shows an aquaplanet configuration, i.e., continents were neglected.