Sooner or later, you want to leverage Zend_Application better by creating your own resource plugins.
Can leverage above be replaced by utilize?
Leverage means to use something in such a way that a small amount has a big result, much as a lever lets you move a larger load than you would normally be able to. In terms of the statement, Zend can be made more effective with plug ins. That is to say, the plug in means that your web app gets extra functionality from Zend+plug ins than it would from Zend alone.
It is frequently used in finance to mean that a small amount of money (like a house downpayment) can be used to much greater financial effect, such as buying a house.
Utilize is certainly an widely abused word, but that doesn't mean it can't be used correctly, or should I say utilized correctly.
According to dictionary.com (my emphasis):
You can make the replacement, but it would change the meaning.
Yes, but mostly because both are terrible word choices.
Leverage as a verb is either (a) an unnecessary neologism meaning 'to use'; (b) a term for investing with borrowed money, or any economically equivalent act.
'Utilize' is simply an ugly variant of 'use'.
Your choices are between 'use', and 'employ'. I suggest that 'employ' would be better, but in any case the whole sentence is awful ('Sooner or later' + present perfect, 'use/leverage/utilize sth better'). Something better might be 'Eventuallly, you will want to better employ Zend Application, by creating your own resource plugins'.