I was working on a large source file (which badly needs refactoring, but that shouldn't be the issue :)) It's 6000+ lines divided into multiple regions. The larghest chunck of code is made up by the inilialize zomponent function (3500 lines), mostly due to componentone proprtybags for their TrueDBGrid.
It might be a good idea to disable syntax highlighting for this function alltogether. Another option I'd love is for Syntax highlighting to disable (something like the "IE has detected a slow script") when it's taking too long.
After approximately one hour of working, updating multiple grids, debugging and some event handlers VS started spewing out OutOfMemoryExceptions. When looking at the taskmanager VS had 300Mb phys and 900Mb swap in use. Normally this is something like 100Mb phys, 150mb swap with the solution loaded.
Another thing I noticed is that hitting reformat code on a file of that size completely hangs VS for more than 15 minutes (and usually get's taskkilled by me long before that).