Yes, that's an issue, but only if you don't want to make your Qt client Free Software. Since nowadays most client-side applications are tied to some web service anyway, releasing those as Free Software might even be advantageous.

Having said that, statically linked wxWidgets .exe files are usually smaller than Qt .exe files. Moreover, dynamically linking to Qt does have technical advantages for certain types of applications (mostly plugin architectures).

Shameless plug: You can create all variants (Qt or wxWidget, each statically or dynamically linked) very conveniently on your Linux build server via cross-compiling, which has become really easy thanks to the MXE project that I started in 2007.

http://mxe.cc

Thanks so much for MXE, it made cross-platform application development much less painful for me.

The LGPL requirement is relinkability, which implies either distributing object files for your application (rare, inconvenient), or, more commonly, linking the LGPL library as a shared object. But that shared object could be stripped down to contain only the symbols your app uses (and their transitive dependants) — just as long as someone can do the same and use their API-matched .so as a drop-in replacement.