Removing the GLib dependency is straightforward for any developer. GLib is used for a few ADTs like variable length strings, hash tables and arrays.
Not sure you understand the problem space... First, newlib is wholly different from GLib, and does not provide the ADTs that GLib provides. Second, replacing GLib and OpenSSL would not change resource usage much at all. ADTs, Big Integer support, SHA hashing and ECDSA are required regardless of lib chosen. They would simply be replaced with... code that did the same thing under name other than "OpenSSL" or "GLib."
If I don't understand the problem space then you don't understand the solution space. GLib's ADT heavily depend on glibc-style memory allocation and both depend on GCC extensions and cross-compiling with MinGW instead of Visual Studio or any other native Windows compiler.
Both GLib and OpenSSL are extremely resource intensive and the only way to get respectable performance out of them is by running on a host with paging MMU and TLB. This excludes majority of standalone / lightweight OSes.
The problem/solution space doesn't demand OpenSSL. It requires BigNums, ECDSA, SHA-256. Any multiuser OS is just a serious hindrance for an lightweight implementation on a lean hardware. All those tasks are best performed not on the main CPU but on the attached GPU or DSP array. When the GPU can be directly called without the overhead of going through OpenGL/OpenCL the whole new world of possibilities opens up. As far as I know currently only PowerVR GPUs have an open source toolchain. This means Texas Instruments OMAP chips. In a year or two probably someone will do the same for the Broadcom VideoCore chips in Raspberry Pi. The performance and power efficiency gained from MIMD implemenations will be immense.
It will soon be building on MacOSX and Windows.
The salient point for Windows is: is it going to be possible to build it using a native Windows compiler like Visual Studio, OpenWATCOM or Borland/Embarcadero? Because another MinGW-only deliverable will be impossible to integrate into the Windows ecosystem.