I want to say that I am big fan of Jobs and Ive and I loved all of his designs.
With that, Ive isn't without fault. Many of his designs, while aesthetically pleasing, have been technical nightmares and have had problems. Someone mentioned it in another thread about iMac and MBP designs as far as replacing parts or harddrives. What about the Macbook discoloration and cracking? iPods catching on fire or was that Macbook Pro's? iPhone 4 antennas or glass breaking? Replace the battery in a iPad or iPhone? Nope, just swap it out. Some of the laptop designs are questionable (to me) as well, regarding soldering of SSD and CPU's chips and stuff like that.
I'm not sensationalizing these issues but they are real. Maybe a change in design is what we need. Keep it minimalistic but allow for more easier upgrading instead of these closed designs. I dunno what the solution is, but Jonny Ive is not without fault in a lot of these designs.
My thoughts are that Apple can't survive a double whammy loss of Steve and Jonny. If they find a strong replacement for Jonny (if he leaves) and Steve is able to implant the "vision" to the new guy, they should be ok.