Re: "will they be improving the resolution of the game"
Which resolution?
The screen resolution? Thats already as high as any other game.
The texture resolution? The game already supports replacement texture packs, which can be significantly higher resolution than the default textures. These can actually look very nice (particularly combined with a shader mod), but the blockyness of the default textures feels like a better fit for size of the blocks.
The size of the blocks? No, this is unlikely to change, the current size is a good compromise between having enough detail to tell whats going on and not having to place too many blocks to build something in a reasonable time.
The polygon count of models for blocks and other entities? Possibly, I think they're working on making models replacable (like textures already are) in a future relealse. As with textures it is likely that some of the third party models will be more detailed than the defaults.