Very few issues with source compatibility
- Requires a side-by-side install with 1.x and 2.0, this is the first time a side by side has been implemented since 1.1 replaced 1.0. Is this the return of dll hell?
- By default a 1.x app will not run on 2.0, unless 1.x is not available (not preferred). A system policy or app.config can "float" a 1.x binary up to a 2.0 framework, but it is user beware.
Delphi 8 can develop for 2.0, but you must rebuild the rtl with 2.0. See Allen Bauer's The Oracle at Delphi