Obviously there has already been a ton of banter about all the basic elements of the Magus. I think a few tweaks would really satisfy a huge majority of the issues many people have with the class in its current form. I would propose the following:
1) Either a d10 hit die OR full BAB. This would bolster the livability of the class, without making it as equally potent as the fighter or barbarian, as well as give it some more incentive for a melee combatant over the bard/summoner. You don't need both, just one or the other in my opinion, and I know it's not standardized with the other base classes, but I think it balances.
2) The addition of more touch spells (as has been routinely brought up. Even just vampiric touch would make me happy)
3) The ability to later channel AOE spells through a single standard attack (such as fireball, but you don't get a reflex save and automatically take half damage)
4) Not needing to have a free hand when casting spells via spellstrike, and only when using spellstrike. If this needs to be only with a bonded weapon in hand, I think that is fair. Also, I think Spellstrike should be clarified to a single standard action, ramping up to working with a full attack action, with the spell effecting only the first target struck, if you attack multiple targets
5) Changing the Magus to a Spontaneous caster, keeping a similar progression of spells per day, and maybe adding 2 spells known per level instead of adding them to a spell book.
6) Remove the Fighter training class feature. It is unnecessary to the progression of a Magus, since I would say the idea is not to mimic a fighter's abilities, but to interweave competent martial abilities with spellcasting.
I don't think any of that throws the Magus out of balance with any of the other classes, and allows for more versatility. In 3.5 I used the Duskblade A LOT (favorite class), and so am well aware of how easily a caster/fighter can get out of hand compared to other classes. I know, I know, I know Jason Buhlman has aid they will not be making a full BAB but I really don't think that would unbalance the magus. If there is really such a huge aversion to it, then I would recommend The magus get a few more castings per day, in order to compensate with the Arcane Accuracy magus arcana.
There you have it folks! Have fun, and play nice in the sandbox :)