Synaptic should check space on /boot

I have a /boot partition it's 50Mb large. When I let synaptic add more and more kernels (since synaptic never seem to delet them), once in a while apt will install the package although there's not enough free space, not the whole file will be written to /boot and no warning is shown at all. The next boot using the default selection in grub will then fail with a strange message.

It would be nice if it warned me before hand (true for everything else too).
It would also be great if packages could be marked as deprecated so that synaptic (or future package manager) actually removes unused kernels (3-4 updates old)