I'am not aaware of a replacement that has full .htaccess support.
The main problem with missing .htaccess support is that poeple rent a webspace, then e.g. install wordpress in it and without .htaccess support, things like the nice url extensions wont work and the the hosting provider will get the complaints that the webspace wornt wor.
There are some workarounds for ngingx an other servers, but as far as I know, they all use a different syntax and are not configured trough a simple drop-in file.
So we might support nginx in a lter version, but this will not be a complete replacement for apache. It will just be a faster alternative for servers that dont need all the apache features.
By the way, have you already tried to fine-tune your apache setup? There are large sites hosted on apache systems, so it should be possible to get a good and fast setup for most situations with apache as well.