Quicken 2007 won't work on Lion due to Apple's decision to drop Rosetta support. This is possibly the final blow for thousands of Mac users who were bitterly disappointed last year by the latest version of Quicken - Quicken Essentials - because of the decision to drop online features such as the ability to pay bills, store investment transaction history and export to TurboTax. If there were ever an example of a developer trying to their best to alienate Mac users and destroy their own product, it's definitely Quicken creators Intuit.
However, the good news is there's no reason to let Intuit or Quicken 2007 stop you from upgrading to Lion. Here is the only selection you'll ever need of the very best alternatives for Lion:
While Moneydance may not feel quite as intuitive as Quicken for Mac at first, it can do pretty much everything the latter can and was actually one of the first ever financial applications on the Mac so it's certainly not lacking in experience. Most importantly, unlike the majority of financial software for Macs, it supports extensive online banking and bill payment features. You can retrieve credit card statements and bank statements from most major US banks that support OFX standards. Even better, you can use Moneydance to automatically pay your bills for you too and if you're worried about all your Quicken data, Moneydance will import it all from Quicken Essentials.
Along with Moneydance, iBank is another excellent alternative for Quicken users. iBank has come a long way since its initial release and is now probably one of the best personal finance apps available on Mac. Like Moneydance, it supports lots of online banking and bill payment features and it will import all of your Quicken data. Unlike Moneydance, it can even scan documents and receipts and attach them to accounts for better organization and finance tracking and there's also an iPhone app. You might notice some imperfections when importing data from Quicken 2007 but nothing you can't tidy-up quickly. iBank takes a bit of getting used to after Quicken but it has an extensive manual and plenty of tutorials to get you going. There's also an active forum of users where you can get help and suggest new features to the developers IGG Software who most users report are very responsive to problems and requests.
MoneyWell offers many of the above although it's aimed more at people that want to focus on budgeting rather than financial management in general. However, as a result it's got a gentler learning curve than either iBank or MoneyDance and is easy to get up and running with. The downside of this is that it lacks some of the more powerful features of the latter such as single line transactions and the ability to pay bills online. It does however support direct connect banking, envelope budgeting, transaction and cash flow management and iPhone integration for budgeting on the move.
Squirrel is the most basic of the financial applications listed here but it's probably the slickest for OS X and a very promising one that could soon rival the likes of iBank and Moneydance. It's by far the easiest to get started with and features enough for basic budgeting such as scheduled transactions, smart folders, sick graphical reports and importing from Quicken. There's also an iPhone app and the developer has offered free updates up until version 2.0 which isn't bad considering it's not even version 1 yet. However, the developer really needs to get a move-on and and add the online banking and bill payment features that it's sorely lacking.
If I had to pick any of the above as the most complete alternative to Quicken 2007, it would be a toss-up between iBank and Moneydance. If you like budgeting on the move and a slick interface, then it would have to be iBank. Moneydance is probably slightly more professional but the Java interface lets it down considerably.
If however you simply can't face leaving Quicken 2007 behind, then you've only got one option. Install Parallels (or any other Virtual Machine) and a version of Snow Leopard and run Quicken 2007 that way. Alternatively, you could run Windows in Parallels and run Quicken for Windows which is much better and fully featured than Quicken 2007 for Mac anyway.