Yup, am OK for disk space (~200 GB free), no other JRE or JDK installed on the system. This happens while doubleclicking from finder - haven't tried any other method. Also note that this does not happen for the beta 8 installer.
Either way, I sampled the log, and both the footprint (2.5 GB) and call graph for the beta 9 installer looks fairly insane. I sampled the process for a second, and the top calls are:
7617 _NSAccessibilityEntryPointValueForAttribute.llvm.BD8B677 (in AppKit) + 182 [0x7fff438d02d7]
7611 NSAccessibilityPerformEntryPointObject.llvm.BD8B677 (in AppKit) + 16 [0x7fff438d010b]
7571 NSAccessibilityGetObjectForAttributeUsingLegacyAPI (in AppKit) + 371 [0x7fff4331e273]
6898 -[JavaComponentAccessibility accessibilityAttributeNames] (in libawt_lwawt.dylib) + 182 [0x1180d1a37]
4213 NSAccessibilityPerformEntryPointBOOL.llvm.BD8B677 (in AppKit) + 16 [0x7fff438d066d]
3993 _NSAccessibilityEntryPointIsAttributeSupported.llvm.BD8B677 (in AppKit) + 101 [0x7fff438d0822]
3879 ___NSAccessibilityEntryPointIsAttributeSupported_block_invoke.llvm.BD8B677 (in AppKit) + 322 [0x7fff438d3cbe]
3811 ValueOfAttributeWithDefault.llvm.3D055F6B (in AppKit) + 56 [0x7fff43674f3d]
3545 JavaAccessibilityAttributeValue (in libawt_lwawt.dylib) + 135 [0x1180cf595]
3503 JavaAccessibilityAttributeValue (in libawt_lwawt.dylib) + 30 [0x1180cf52c]
551 JavaAccessibilityAttributeValue (in libawt_lwawt.dylib) + 107 [0x1180cf579]
526 +[NSString stringWithFormat:] (in Foundation) + 169 [0x7fff47e09b31]
509 -[AWTView accessibilityAttributeValue:] (in libawt_lwawt.dylib) + 242 [0x1180a5ef2]
334 -[AWTView accessibilityAttributeNames] (in libawt_lwawt.dylib) + 68 [0x1180a5f3f]
290 _CFStringCreateWithFormatAndArgumentsAux2 (in CoreFoundation) + 116 [0x7fff45cb9034]
274 -[NSArray arrayByAddingObject:] (in CoreFoundation) + 283 [0x7fff45d2aeeb]
I dunno if this is a bug in the JRE used in the installer or in AppKit, but the result is an application that tends up using gigabytes of memory and 100% CPU