Mostly. The limitation is largely based on device storage: my small modem (64 MB RAM, 8 MB Flash) has only a ~5 MB /overlay partition, which is rapidly filled (as I've discovered).
On a device with more nonvolatile storage, you can run more opkg updates and installs.
Alternatively, build and install your own images, if that's your thing. I've tried this, unsuccessfully to date.
