OK. Thanks at least for some information. It looks like my 6 yr old Mac is now too old to run Minecraft as it is only 32 bit and I can't seem to find out if I can get Java 6 for it 😞
It would be great if in future if there are updates which require you to have certain computer specs / operating systems that Mojang make some mention of this on their blog eg. 'this requires you to have Java 6 or higher - for more info click here...' . If I had known this was coming I would have done something about getting a new computer in the last financial year.
Um, sorry but why is this marked as 'Resolved'? It is not resolved - I still can't open the launcher and so can't play.
If you have an old Mac running OSX 10.5.8 Leopard with 32 bit you can't get Java 6 (aka Java 1.6). This means you can't run the new launcher and so can't play Minecraft 1.6.2 . The old launcher will only run Minecraft 1.5.2 .
This was my situation so I had to upgrade my OS to 10.6 Snow Leopard. This comes with Java 6 and now I can finally run Minecraft again. You will probably need to do the same. Upgrading your OS is cheaper than buying a new computer at least.
Good luck