Is there a way to workaround the phone memory limit for installed apps? ..without rooting my phone.

Does this mean I really can't keep all the apps I want, and I have to clear data or uninstall apps when I want to install a new app that doesn't fit the phone memory?

Does anyone know if Google has any plans of doing away with this restriction?
Your phone needs space for upgrades, temp files, and the like.  You can't fill it up to the brim any more than you can fill the hard drive a computer OS is on.  Google will not do away with it.

If you are out of space and your phone doesn't take an SD card, then yes you will have to clear up space for new apps.  If it takes an SD card and you have root or 2.2+, you should be able to move many of your apps onto it (search for how), and App2SD support is being encouraged.