Synopse

The currency type is the standard Delphi type to be used when storing and handling monetary values. It will avoid any rounding problems, with 4 decimals precision. It is able to safely store numbers in the range -922337203685477.5808 .. 922337203685477.5807. Should be enough for your pocket change.

As stated by the official Delphi documentation:

Currency is a fixed-point data type that minimizes rounding errors in monetary calculations. On the Win32 platform, it is stored as a scaled 64-bit integer with the four least significant digits implicitly representing decimal places. When mixed with other real types in assignments and expressions, Currency values are automatically divided or multiplied by 10000.

In fact, this type matches the corresponding OLE and .Net implementation of currency, and the one used by most database providers (when it comes to money, a dedicated type is worth the cost in a "rich man's world"). It is still implemented the same in the Win64 platform (since XE 2). The Int64 binary representation of the currency type (i.e. value*10000 as accessible via PInt64(aCurrencyValue)^) is a safe and fast implementation pattern.

In our framework, we tried to avoid any unnecessary conversion to float values when dealing with currency values. Some dedicated functions have been implemented for fast and secure access to currency published properties via RTTI, especially when converting values to or from JSON text. Using the Int64 binary representation can be not only faster, but also safer: you will avoid any rounding problem which may be introduced by the conversion to a float type. Rounding issues are a nightmare to track - it sounds safe to have a framework handling natively a currency type from the ground up.

For those how are interested in FireMonkey, I made some screenshots of some DXScene sample app.

It may give you some good starting point about the features of the upcoming Delphi XE2 user interface components.

Speaking about [upcoming] 64 bit Delphi compiler, I did forecast they will surely release their compiler 5 years later than FPC's... hoping they will follow the FPC way, just as Intel did about 64 bits instructions, against AMD.

What I was referring to is that AMD was the first to publish a 64 bit x86 CPU, with a new instruction set. Intel released somewhat later their own 64 bit x86 CPU, following the same instruction set.
There are some variants between AMD and Intel CPU, some dedicated instructions or implementations.
But most instruction set is perfectly compatible.

And I suspect the more it gets, the less compatible FPC and Delphi will be.

The main difference between Delphi and FPC is that the first is a business company project (Embarcadero), the second an Open Source solution. They are not two billions dollars companies fighting each other, with some state-level institutions watching about any unfair competition or monopoly... FPC compiler is technically a great and robust project, but EMB follows business rules. I don't think anyone will play "Anti-monopoly" in favor of FPC.

In a recent thread in the Embarcadero Discussion Forums, Vedran Vuk posted some questions about object keyword.
His purpose was to use object instead of class to improve speed and memory consumption: 

I do use classes. I just want to use objects on smaller classes that don't really need initialization or RTTI. Plus, I can directly operate on it like a record with no need for constructors and it can be sealed and has inheritance. Every byte matters in this case.

In a very interesting comment, PhiS spoke about the Mac OS X Stack Alignment problem, and the way asm code should be written for the future Cross Platform Delphi compiler. Here are some (hope without any Troll hidden) reflections I went through.