Always on the lookout for new graphics tools, I ran across an interesting entrant from 61 Solutions named Mischief.
With its clean, uncluttered interface, Mischief is a good alternative for the Surface Pro's small screen. Although at first glance, the software appears to have limited functionality, it has one distinguishing feature: what its developers call an "infinite canvas." The effect is like a fractal image that can be zoomed to reveal increasing levels of detail. In fact, it is very easy to draw items so small they cannot be perceived when the image is zoomed to its beginning size.
Mischief uses Adaptively Sampled Distance Fields (ADFs), originally invented and developed at Mitsubishi Electric Research Laboratories (MERL) and further enhanced at 61 Solutions. ADFs are a new digital representation of shape which provide numerous advantages including high-quality anti-aliasing, very fast rendering, very small file sizes, multi-scale rendering, support for massive parallelism, and the ability to succinctly represent variable-width, scalable, textured strokes. This technology is protected by over 50 patents.
Similar effects may be achieved with vectors in other programs, but in Mischief functions are performed with standard paint or raster tools.
Although it's relatively inexpensive at $65, I really can't recommend Mischief due to its relatively limited toolset, but if you're looking for a program that can produce extremely high resolution work, Mischief might be for you.